Preparation and uses of reactive oxygen species scavenger derivatives

ABSTRACT

Compounds of Formula (I)a or (I)b: 
                         
including certain quinone derivatives, and the corresponding pharmaceutical compositions, which may serve to modulate ferroptosis in a subject. Also disclosed herein are the preparations of these compounds and pharmaceutical compositions and their potential uses in the manufacture of a medicament in reducing reactive oxygen species (ROS) in a cell and for preventing, treating, ameliorating certain related disorder or a disease.

This application claims the benefit under 35 U.S.C. § 111(a) of PCTInternational Application No. PCT/CN2017/097805 filed on Aug. 17, 2017,which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention provides compositions and methods useful fortreatment or suppression of diseases, developmental delays and symptomsrelated to oxidative stress. More specifically, the compositions andmethods comprise administrating an effective amount of a compound thatis a ferroptosis modulator.

BACKGROUND OF INVENTION

While localized ROS (reactive oxygen species) are critical to theeukaryotic cell's biological metabolism and development, excessive fluxof unrestrained ROS leads to cellular dysfunctions and/or death.

Since its introduction in 2012, ferroptosis has emerged as a keymechanistic pathway for excess ROS flux (especially in the mitochondria)which ultimately leads to non-apoptotic cell death. As the key elementin ferroptosis, the loss of glutathione peroxidase 4 (GPx4) activityallows for a lethal excess of ROS which then leads to cellulardestruction by oxidative stress. Since GPx4 uses glutathione (GSH) asthe key co-factor for scavenging ROS, GSH production deficit can arisefrom blocked induction (e.g., via known small compounds such as erastinand excess glutamates) of its ‘up-stream’ Xc system (a glutamate/cystineanti-transporter). On the other hand, inducing excess ROS flux viaferroptosis can kill certain cancer cells.

Based on the above reviews as well as references about some otherinhibitors attributable to their anti-ferroptotic mechanisms of action(e.g., ferrostatins: patent applications—US 2016/0297748 and WO2013/152039, quinones such as MitoQ, small peptides such as SS-31:(https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4267688/accessed Jul. 7,2017 and patent publication WO2004070054 (A2)); nitroxides such asXJB-5-131 and JP4-039 analogs (patent publication WO2012112851 (A2)).XJB-5-131 has also been applied in the application of inhibition offerroptosis, wherein it plays a critical role of intramitochondriallipid peroxidation in ferroptosis. Also, the reference compoundferrostatin-1 and XJB-5-131 may share similar mechanisms of action orthat both compounds operate on the same signaling pathway. Ferroptosiscan be linked to a variety of well-known diseases broadly grouped asinvolving the non-central nervous system (non-CNS) or CNS.

Non-CNS: cardiovascular (e.g., atherosclerosis, hypertensivecardiomyopathy, congestive heart failure, stroke, etc.), metabolic(e.g., diabetes and its related complications such as neuropathy,hyperlipidemia, etc.), urinary (e.g., acute kidney injury (AKI)), agerelated diseases (e.g., skeletal muscle atrophy, and dry aged maculardegeneration (Dry-AMD) and trauma (e.g., radiation injury, inducingrhabdomyolysis, traumatic brain injury, major surgery, etc.). In thecase of AKI, US FDA today has yet to approve a drug to specifically curethis disease which especially affects ˜30% of US patients hospitalizedin intensive care units. When AKI unfortunately progresses to thelate/chronic stages, hemo-dialysis and ultimately kidney replacementbecome the major remaining treatment options.

CNS: neuro-motor (e.g., Parkinson's, Huntington's, amyotrophic lateralsclerosis, epilepsy, etc.) and cognitive (e.g., Alzheimer's). In thecase of epilepsy which affects over 50 million people globally, asignificant minority (20-30%) of patients are/become resistant to morethan 20 currently approved drugs. Undoubtedly, ongoing research willlikely link more diseases due to and more inhibitors of ferroptosissince its 2012 introduction. Thus as exemplified by AKI and epilepsysome other diseases to be linked to ferroptosis in the future alsourgently need better (likely novel) drugs.

SUMMARY OF THE INVENTION

The following is only an overview of some aspects of the presentinvention, but is not limited thereto. All references of thisspecification are incorporated herein by reference in their entirety.When the disclosure of this specification is different with citations,the disclosure of this specification shall prevail. The presentinvention provides compounds and pharmaceutical compositions, whichmodulates ferroptosis in a subject; include certain quinone derivatives,their preparation, and the corresponding pharmaceutical compositions.The compounds and/or pharmaceutical compositions of the presentinvention can be potentially used in the manufacture of a medicament forpreventing, treating, ameliorating certain disorder or a disease in apatient.

One aspect of the present invention is the provision of a compound ofthe following Formula (I)a or (I)b, pharmaceutically acceptable saltsand individual enantiomers or diastereomers thereof.

Wherein z is 0 or 1;

-   -   L is absent, or is selected from a group consisting of: C1-C10        alkyl, C1-C10 alkoxyl, cycloalkyl, C1-C10 alkylcycloalkyl,        heterocycloalkyl, C1-C10 alkylheterocycloalkyl, aryl, C1-C10        alkylaryl, heteroaryl, and C1-C10 alkylheteroaryl, wherein said        cycloalkyl, or heterocycloalkyl has about 3 to about 7 ring        carbons, and said aryl or heteroaryl has about 5 to about 10        ring carbons;        Q is selected from a group consisting of:

wherein n is an integer selected from 0 to 10;

-   -   R₁ or R₂ is H or CH₃;    -   R₃ or R₄ is H or C1-C5alkyl;    -   W is absent, O or S; and    -   i) when W is absent, R₃ and R₄ can, optionally, together form        the following structure:

-   -   ii) when W is O, OR₃ and OR₄ can, optionally, together form the        following structure:

PEP is a peptidyl moiety having the following structure:

wherein a * mark denotes a chiral center in either an (S) or (R)configuration and m is an integer selected from 0 to 10;

X₁ is selected from a group consisting of H, —(C═O)—O-Rm, —(SO)—O-Rm,—(SO₂)—O-Rm, —(SO₂)—N-(Rm)₂, and —(C═O)—N-(Rm)₂, where Rm is C1-C6alkyl, C1-C6 alkoxyl, C1-C6 alkenyl, C1-C6 haloalkyl, cycloalkyl, C1-C6alkylcycloalkyl, heterocycloalkyl, C1-C6 alkylheterocycloalkyl, aryl,C1-C6 alkylaryl, heteroaryl, and C1-C6 alkylheteroaryl, wherein saidcycloalkyl, or heterocycloalkyl has about 3 to about 7 ring carbons, andsaid aryl or heteroaryl has about 5 to about 10 ring carbons;

X₂, X₃ or X₄ is selected from a group consisting of C1-C10 alkyl, C1-C10alkenyl, aryl, C1-C6 alkylaryl, heteroaryl, C1-C6 alkylheteroaryl,wherein said aryl or heteroaryl having from 5 to 6 ring carbons;

A is absent or selected from a group consisting of: Ala, Leu, Ile, Phe,Met, Pro, Gly, Ser, Thr, Cys, Tyr, Asn, Gln, His, Lys, Arg, Asp, Glu,and Val, each of which can be in either a D or L configuration; whereinthe amino residue is either unprotected, or protected by a protectinggroup selected from a group consisting of Cbz and Fmoc;

G is absent, or selected from a group consisting of: —O—, —S—, —NH—,—NH—(C═O)—O—, —O—(C═O)—NH—, —NH—(C═O)—NH—, —NHSO₂—, —SO—, and —SO₂—.

A further aspect of the present invention is the provision of a compoundof the aforementioned Formula (I)a or (I)b, wherein PEP is preferably

wherein a * mark denotes a chiral center that can be either in an (S) or(R) configuration;

X₁ is selected from a group consisting of H, —(C═O)—O-Rm, —(SO)—O-Rm,—(SO₂)—O—Rm, —(SO₂)—N-(Rm)₂, and —(C═O)—N-(Rm)₂, where Rm is C1-C6alkyl, C1-C6 alkoxyl, C1-C6 alkenyl, C1-C6 haloalkyl, cycloalkyl, C1-C6alkylcycloalkyl, heterocycloalkyl, C1-C6 alkylheterocycloalkyl, aryl,C1-C6 alkylaryl, heteroaryl, and C1-C6 alkylheteroaryl, wherein saidcycloalkyl, or heterocycloalkyl has about 3 to about 7 ring carbons, andsaid aryl or heteroaryl has about 5 to about 10 ring carbons;

X₂, X₃ or X₄ is selected from a group consisting of C1-C10 alkyl, C1-C10alkenyl, aryl, C1-C6 alkylaryl, heteroaryl, C1-C6 alkylheteroaryl,wherein said aryl or heteroaryl having from 5 to 6 ring carbons.

A is absent or selected from a group consisting of: Ala, Leu, Ile, Phe,Met, Pro, Gly, Ser, Thr, Cys, Tyr, Asn, Gln, His, Lys, Arg, Asp, Glu,and Val, each of which can be in either a D or L configuration; whereinthe amino residue is either unprotected, or protected by a protectinggroup selected from a group consisting of Cbz and Fmoc.

In a further aspect, the invention relates to pharmaceuticalcompositions each comprising an effective amount of at least onecompound of Formula (I)a or (I)b or a pharmaceutically acceptable saltof a compound of Formula (I)a or (I)b, and individual enantiomers anddiastereomers thereof. Pharmaceutical compositions according to theinvention may further comprise at least one pharmaceutically acceptableexcipient, carrier, adjuvant, solvent, support or a combination thereofand may further comprise therapeutically effective amounts of one ormore, optional, adjunctive active ingredients.

In yet another aspect of the present invention, the compounds of Formula(I)a or (I)b or a pharmaceutically acceptable salt of a compound ofFormula (I)a or (I)b, and individual enantiomers and diastereomersthereof, are useful as ferroptosis modulators. Thus, the invention isdirected to the use of an effective amount of at least oneaforementioned compound of Formula (I)a or (I)b or a pharmaceuticallyacceptable salt of a compound of Formula (I)a or (I)b, and individualenantiomers and diastereomers thereof in the manufacture of a medicamentto be used in a method for reducing reactive oxygen species (ROS) in acell comprising contacting a cell with an effective amount of saidcompound as a ferroptosis modulator.

In still another aspect of the present invention, there is directed to amethod for modulating ferroptosis in a subject, comprising exposing thesubject to an effective amount of at least one compound of Formula (I)aor (I)b, or a pharmaceutically acceptable salt of a compound of Formula(I)a or (I)b, and individual enantiomers and diastereomers thereof, andat least one pharmaceutically acceptable excipient, carrier, adjuvant,solvent, support or a combination thereof, and further therapeuticallyeffective amounts of one or more, optional, adjunctive activeingredients.

Another aspect of the present invention concerns the use ofpharmaceutical compositions each comprising an effective amount of atleast one compound of Formula (I)a or (I)b or a pharmaceuticallyacceptable salt of a compound of Formula (I)a or (I)b, and individualenantiomers and diastereomers thereof, and at least one pharmaceuticallyacceptable excipient, carrier, adjuvant, solvent, support or acombination thereof, and further therapeutically effective amounts ofone or more, optional, adjunctive active ingredients, in the manufactureof a medicament for preventing, treating or lessening an oxidativestress related disorder or disease in a patient by administeringtherapeutically effective amounts of said compound or saidpharmaceutical composition as a ferroptosis modulator.

In yet another aspect, the invention is directed to a method forpreventing, treating or lessening an oxidative stress related disorderor disease in a patient by modulating certain ferroptosis process insaid patient by administering to the patient a therapeutically effectiveamount of the aforementioned pharmaceutical compositions each comprisingan effective amount of at least one compound of Formula (I)a or (I)b ora pharmaceutically acceptable salt of a compound of Formula (I)a or(I)b, and individual enantiomers and diastereomers thereof, and at leastone pharmaceutically acceptable excipient, carrier, adjuvant, solvent,support or a combination thereof, and further therapeutically effectiveamounts of one or more, optional, adjunctive active ingredients.

In yet another aspect, the present invention is directed to methods ofmaking compounds of Formula (I)a or (I)b and pharmaceutically acceptablesalts thereof.

In certain embodiments of the compounds, pharmaceutical compositions,and methods of the invention, the compound of Formula (I)a or (I)b is acompound selected from those species described or exemplified in thedetailed description below, or is a pharmaceutically acceptable salt ofsuch a compound.

Another preferred embodiment, the present invention is directed tomethods of preparing pharmaceutical compositions each comprising aneffective amount of at least one compound of Formula (I)a or (I)b, or apharmaceutically acceptable salt of a compound of Formula (I)a or (I)b,and further individual enantiomers and diastereomers thereof. Asaforementioned, pharmaceutical compositions according to the inventionmay further comprise at least one pharmaceutically acceptable excipient,carrier, adjuvant, solvent, support or a combination thereof and furthercomprise therapeutically effective amounts of one or more, optional,adjunctive active ingredients.

If formulated as a fixed dose, such combination products employ thecompounds of this invention within the dosage range described herein (oras known to those skilled in the art) and the other pharmaceuticallyactive agents or treatments within its dosage range. For example, theCDC2 inhibitor olomucine has been found to act synergistically withknown cytotoxic agents in inducing apoptosis (J. Cell Sci., (1995) 108,2897). The compounds of the invention may also be administeredsequentially with known anticancer or cytotoxic agents when acombination formulation is inappropriate. In any combination treatment,the invention is not limited in the sequence of administration;compounds of Formula (I)a or (I)b may be administered either prior to orafter administration of the known anticancer or cytotoxic agent. Forexample, the cytotoxic activity of the cyclin-dependent kinase inhibitorflavopiridol is affected by the sequence of administration withanticancer agents (Cancer Research, (1997) 57, 3375). Such techniquesare within the skills of persons skilled in the art as well as attendingphysicians.

Any of the aforementioned methods may be augmented by administration offluids (such as water), loop diuretics, one or more of achemotherapeutic or antineoplastic agent, such as leucovorin andfluorouracil, and an adjunctive chemotherapeutic agent (such asfilgrastim and erythropoietin), or any combination of the foregoing.

Yet another embodiment is a method for administering a compound of theinstant invention to a subject (e.g., a human) in need thereof byadministering to the subject the pharmaceutical formulation of thepresent invention.

Yet another embodiment is a method of preparing a pharmaceuticalformulation of the present invention by mixing at least onepharmaceutically acceptable compound of the present invention, and,optionally, one or more pharmaceutically acceptable additives orexcipients.

For preparing pharmaceutical compositions from the compounds describedby this invention, inert, pharmaceutically acceptable carriers can beeither solid or liquid. Solid form preparations include powders,tablets, dispersible granules, capsules, beads, cachets andsuppositories. The powders and tablets may be comprised of from about 5to about 95 percent active ingredient. Suitable solid carriers are knownin the art, e.g., magnesium carbonate, magnesium stearate, talc, sugaror lactose. Tablets, powders, cachets and capsules can be used as soliddosage forms suitable for oral administration. Examples ofpharmaceutically acceptable carriers and methods of manufacture forvarious compositions may be found in A. Gennaro (ed.), Remington'sPharmaceutical Sciences, 18th Edition, (1990), Mack Publishing Co.,Easton, Pa.

Liquid form preparations include solutions, suspensions and emulsions.As an example may be mentioned water or water-propylene glycol solutionsfor parenteral injection or addition of sweeteners and opacifiers fororal solutions, suspensions and emulsions. Liquid form preparations mayalso include solutions for intranasal administration.

Aerosol preparations suitable for inhalation may include solutions andsolids in powder form, which may be in combination with apharmaceutically acceptable carrier, such as an inert compressed gas,e.g., nitrogen.

Also included are solid form preparations that are intended to beconverted, shortly before use, to liquid form preparations for eitheroral or parenteral administration. Such liquid forms include solutions,suspensions and emulsions.

The compounds of the invention may also be deliverable transdermally.The transdermal compositions can take the form of creams, lotions,aerosols and/or emulsions and can be included in a transdermal patch ofthe matrix or reservoir type as are conventional in the art for thispurpose.

The compounds of this invention may also be delivered subcutaneously.

Preferably the compound is administered orally or intravenously or viaan eye drop or an intravitreous injection

Preferably, the pharmaceutical preparation is in a unit dosage form. Insuch form, the preparation is subdivided into suitably sized unit dosescontaining appropriate quantities of the active component, e.g., aneffective amount to achieve the desired purpose.

The actual dosage employed may be varied depending upon the requirementsof the patient and the severity of the condition being treated.Determination of the proper dosage regimen for a particular situation iswithin the skill of the art. For convenience, the total daily dosage maybe divided and administered in portions during the day as required. Theamount and frequency of administration of the compounds of the inventionand/or the pharmaceutically acceptable salts thereof will be regulatedaccording to the judgment of the attending clinician considering suchfactors as age, condition and size of the patient as well as severity ofthe symptoms being treated.

Any embodiment disclosed herein can be combined with other embodimentsas long as they are not contradictory to one another, even though theembodiments are described under different aspects of the invention. Inaddition, any technical feature in one embodiment can be applied to thecorresponding technical feature in other embodiments as long as they arenot contradictory to one another, even though the embodiments aredescribed under different aspects of the invention.

The foregoing merely summarizes certain aspects disclosed herein and isnot intended to be limiting in nature. These aspects and other aspectsand additional embodiments, features, and advantages of the inventionwill be apparent from the following detailed description and throughpractice of the invention.

DETAILED DESCRIPTION AND PARTICULAR EMBODIMENTS

For the sake of brevity, the disclosures of the publications cited inthis specification, including patents and patent applications, areherein incorporated by reference in their entirety.

Most chemical names were generated using IUPAC nomenclature herein. Somechemical names were generated using different nomenclatures oralternative or commercial names known in the art. In the case ofconflict between names and structures, the structures prevail.

Definitions and General Terminology

Reference will now be made in detail to certain embodiments of theinvention, examples of which are illustrated in the accompanyingstructures and formulas. The invention is intended to cover allalternatives, modifications and equivalents which may be included withinthe scope of the present invention as defined by the claims. One skilledin the art will recognize many methods and materials similar orequivalent to those described herein, which could be used in thepractice of the present invention. The present invention is in no waylimited to the methods and materials described herein. In the event thatone or more of the incorporated literature, patents, and similarmaterials differs from or contradicts this application, including butnot limited to defined terms, term usage, described techniques, or thelike, this application controls.

It is further appreciated that certain features of the invention, whichare, for clarity, described in the context of separate embodiments, canalso be provided in combination in a single embodiment. Conversely,various features of the invention which are, for brevity, described inthe context of a single embodiment, can also be provided separately orin any suitable sub-combination.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as are commonly understood by one skilled in theart to which this invention belongs. All patents and publicationsreferred to herein are incorporated by reference in their entirety.

As used herein, the following definitions shall apply unless otherwiseindicated. For purposes of this invention, the chemical elements areidentified in accordance with the Periodic Table of the Elements, CASversion, and the Handbook of Chemistry and Physics, 75th Ed. 1994.Additionally, general principles of organic chemistry are described in“Organic Chemistry”, Thomas Sorrell, University Science Books,Sausalito: 1999, and “March's Advanced Organic Chemistry” by Michael B.Smith and Jerry March, John Wiley & Sons, New York: 2007, the entirecontents of which are hereby incorporated by reference.

As used above, and throughout this disclosure, the following terms,unless otherwise indicated, shall be understood to have the followingmeanings. If a definition is missing, the conventional definition asknown to one skilled in the art controls. If a definition providedherein conflicts or is different from a definition provided in any citedpublication, the definition provided herein controls.

As used herein, the terms “including”, “containing” and “comprising” areused in their open, non-limiting sense.

As used herein, the singular forms “a”, “an” and “the” include pluralreferents unless the context clearly dictates otherwise.

To provide a more concise description, some of the quantitativeexpressions given herein are not qualified with the term “about”. It isunderstood that, whether the term “about” is used explicitly or not,every quantity given herein is meant to refer to the actual given value,and it is also meant to refer to the approximation to such given valuethat would reasonably be inferred based on the ordinary skill in theart, including equivalents and approximations due to the experimentaland/or measurement conditions for such given value. Whenever a yield isgiven as a percentage, such yield refers to a mass of the entity forwhich the yield is given with respect to the maximum amount of the sameentity that could be obtained under the particular stoichiometricconditions. Concentrations that are given as percentages refer to massratios, unless indicated differently.

Chemical Definitions

As used herein, “alkyl” refers to a saturated, straight- orbranched-chain hydrocarbon group having from 1 to 12 carbon atoms.Representative alkyl groups include, but are not limited to, methyl,ethyl, n-propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl,2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl,2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl,4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl,4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl,2-ethyl-1-butyl, butyl, isobutyl, t-butyl, n-pentyl, isopentyl,neopentyl, n-hexyl, and the like, and longer alkyl groups, such asheptyl, octyl, and the like. As used herein, “lower alkyl” means analkyl having from 1 to 6 carbon atoms.

The term “alkylamino” as used herein denotes an amino group as definedherein wherein one hydrogen atom of the amino group is replaced by analkyl group as defined herein. Aminoalkyl groups can be defined by thefollowing general formula —NH-alkyl. This general formula includesgroups of the following general formulae: —NH—C1-C10 alkyl and —NH—C1-C6alkyl. Examples of aminoalkyl groups include, but are not limited toaminomethyl, aminoethyl, aminopropyl, aminobutyl.

The term “alkoxy” as used herein includes —O-(alkyl), wherein alkyl isdefined above.

As used herein, “alkoxyalkyl” means -(alkylenyl)-O-(alkyl), wherein each“alkyl” is independently an alkyl group defined above.

The term “amine” as used herein refers to an —NH₂ group.

“Aryl” means a mono-, bi-, or tricyclic aromatic group, wherein allrings of the group are aromatic. For bi- or tricyclic systems, theindividual aromatic rings are fused to one another. Exemplary arylgroups include, but are not limited to, phenyl, naphthalene, andanthracene.

“Aryloxy” as used herein refers to an —O-(aryl) group, wherein aryl isdefined as above.

“Arylalkyl” as used herein refers to an -(alkylenyl)-(aryl) group,wherein alkylenyl and aryl are as defined above. Non-limiting examplesof arylalkyls comprise a lower alkyl group. Non-limiting examples ofsuitable arylalkyl groups include benzyl, 2-phenethyl, andnaphthalenylmethyl.

“Arylalkoxy” as used herein refers to an —O-(alkylenyl)-aryl groupwherein alkylenyl and aryl are as defined above.

The term “deuterium” “deuterated” as used herein means being, beingsubstituted with, a stable isotope of hydrogen having one proton and oneneutron.

The term “halogen” as used herein refers to fluorine, chlorine, bromine,or iodine. The term “halo” represents chloro, fluoro, bromo, or iodo.

The term “haloalkyl” denotes an alkyl group as defined above wherein oneor more, for example one, two, or three of the hydrogen atoms of thealkyl group are replaced by a halogen atom, for example fluoro, bromo,or chloro, in particular fluoro. Examples of haloalkyl include, but arenot limited to, monofluoro-, difluoro-, or trifluoro-methyl, -ethyl or-propyl, for example, 3,3,3-trifluoropropyl, 2-fluoroethyl,2,2,2-trifluoroethyl, fluoromethyl, difluoromethyl, or trifluoromethyl,or bromoethyl or chloroethyl. Similarly, the term “fluoroalkyl” refersto an alkyl group as defined above substituted with one or more, forexample one, two, or three fluorine atoms.

The term “haloalkoxy” as used herein refers to an —O-(haloalkyl) groupwherein haloalkyl is defined as above. Exemplary haloalkoxy groups arebromoethoxy, chloroethoxy, trifluoromethoxy and 2,2,2-trifluoroethoxy.

The term “hydroxy” means an —OH group.

The term “hydroxyalkyl” denotes an alkyl group that is substituted by atleast one hydroxy group, for example, one, two or three hydroxygroup(s). The alkyl portion of the hydroxyalkyl group provides theconnection point to the remainder of a molecule. Examples ofhydroxyalkyl groups include, but are not limited to, hydroxymethyl,hydroxyethyl, 1-hydroxypropyl, 2-hydroxyisopropyl, 1,4-dihydroxybutyl,and the like.

The term “oxo” means an ═O group and may be attached to a carbon atom ora sulfur atom. The term “N-oxide” refers to the oxidized form of anitrogen atom.

As used herein, the term “cycloalkyl” refers to a saturated or partiallysaturated, monocyclic, fused polycyclic, bridged polycyclic, or spiropolycyclic carbocycle having from 3 to 12 ring carbon atoms. Anon-limiting category of cycloalkyl groups are saturated or partiallysaturated, monocyclic carbocycles having from 3 to 6 carbon atoms.Illustrative examples of cycloalkyl groups include, but are not limitedto, the following moieties:

The term “cycloalkoxy” refers to a —O-(cycloalkyl) group.

As used herein, the term “heteroaryl” refers to a monocyclic, or fusedpolycyclic, aromatic heterocycle having from three to 15 ring atoms thatare selected from carbon, oxygen, nitrogen, selenium and sulfur.Suitable heteroaryl groups do not include ring systems that must becharged to be aromatic, such as pyrylium. Some suitable 5-memberedheteroaryl rings (as a monocyclic heteroaryl or as part of a polycyclicheteroaryl) have one oxygen, sulfur, or nitrogen atom, or one nitrogenplus one oxygen or sulfur, or 2, 3, or 4 nitrogen atoms. Some suitable6-membered heteroaryl rings (as a monocyclic heteroaryl or as part of apolycyclic heteroaryl) have 1, 2, or 3 nitrogen atoms. Examples ofheteroaryl groups include, but are not limited to, pyridinyl,imidazolyl, imidazopyridinyl, pyrimidinyl, pyrazolyl, triazolyl,pyrazinyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl,isothiazolyl, pyrrolyl, quinolinyl, isoquinolinyl, indolyl,benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl,phthalazinyl, pyridazinyl, triazinyl, isoindolyl, pteridinyl, purinyl,oxadiazolyl, triazolyl, thiadiazolyl, furazanyl, benzofurazanyl,benzothiophenyl, benzothiazolyl, benzoxazolyl, quinazolinyl,quinoxalinyl, naphthyridinyl, and furopyridinyl.

Those skilled in the art will recognize that the species of heteroaryl,and cycloalkyl groups listed or illustrated above are not exhaustive,and that additional species within the scope of these defined terms mayalso be selected.

As described herein, compounds disclosed herein may optionally besubstituted with one or more substituents, or as exemplified byparticular classes, subclasses, and species of the invention.

As used herein, the term “substituted” means that the specified group ormoiety bears one or more suitable substituents. As used herein, the term“unsubstituted” means that the specified group bears no substituents. Asused herein, the term “optionally substituted” means that the specifiedgroup is unsubstituted or substituted by the specified number ofsubstituents. Where the term “substituted” is used to describe astructural system, the substitution is meant to occur at anyvalency-allowed position on the system.

As used herein, the expression “one or more substituents” denotes one tomaximum possible number of substitution(s) that can occur at anyvalency-allowed position on the system. In a certain embodiment, one ormore substituent means 1, 2, 3, 4, or 5 substituents. In anotherembodiment, one or more substituent means 1, 2, or 3 substituents.

Any atom that is represented herein with an unsatisfied valence isassumed to have the sufficient number of hydrogen atoms to satisfy theatom's valence.

When any variable (e.g., alkyl, alkylenyl, heteroaryl, R₁, R₂, or R_(a))appears in more than one place in any formula or description providedherein, the definition of that variable on each occurrence isindependent of its definition at every other occurrence.

Numerical ranges, as used herein, are intended to include sequentialwhole numbers. For example, a range expressed as “from 0 to 4” or “0-4”includes 0, 1, 2, 3 and 4, while a range expressed as “10-20%” includes10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% and 20%. Similarly,numerical ranges are also intended to include sequential fractionalintegers. For example, a range expressed as “1-2%” would include 1.0%,1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% and 2.0%.

When a multifunctional moiety is shown, the point of attachment to thecore is indicated by a line or hyphen. For example, aryloxy—refers to amoiety in which an oxygen atom is the point of attachment to the coremolecule while aryl is attached to the oxygen atom.

Additional Definitions

As used herein, the term “subject” encompasses mammals and non-mammals.Examples of mammals include, but are not limited to, any member of theMammalian class: humans; non-human primates such as chimpanzees, andother apes and monkey species; farm animals such as cattle, horses,sheep, goats, swine; domestic animals such as rabbits, dogs, and cats;and laboratory animals including rodents, such as rats, mice and guineapigs, and the like. Examples of non-mammals include, but are not limitedto, birds, fish and the like. In one embodiment of the presentinvention, the mammal is a human.

“Patient” includes both human and animals.

The term “inhibitor” refers to a molecule such as a compound, a drug, anenzyme activator, or a hormone that blocks or otherwise interferes witha particular biologic activity.

The term “modulator” refers to a molecule, such as a compound of thepresent invention, that increases or decreases, or otherwise affects theactivity of a given protein, receptor and/or ion channels.

The terms “effective amount” or “therapeutically effective amount” referto a sufficient amount of the agent to provide the desired biologicalresult. That result can be reduction and/or alleviation of the signs,symptoms, or causes of a disease or medical condition, or any otherdesired alteration of a biological system. For example, an “effectiveamount” for therapeutic use is the amount of a compound, or of acomposition comprising the compound, that is required to provide aclinically relevant change in a disease state, symptom, or medicalcondition. An appropriate “effective” amount in any individual case maybe determined by one of ordinary skill in the art using routineexperimentation. Thus, the expression “effective amount” generallyrefers to the quantity for which the active substance has atherapeutically desired effect.

As used herein, the terms “treat” or “treatment” encompass both“preventative” and “curative” treatment. “Preventative” treatment ismeant to indicate a postponement of development of a disease, a symptomof a disease, or medical condition, suppressing symptoms that mayappear, or reducing the risk of developing or recurrence of a disease orsymptom. “Curative” treatment includes reducing the severity of orsuppressing the worsening of an existing disease, symptom, or condition.Thus, treatment includes ameliorating or preventing the worsening ofexisting disease symptoms, preventing additional symptoms fromoccurring, ameliorating or preventing the underlying metabolic causes ofsymptoms, inhibiting the disorder or disease, e.g., arresting thedevelopment of the disorder or disease, relieving the disorder ordisease, causing regression of the disorder or disease, relieving acondition caused by the disease or disorder, or stopping the symptoms ofthe disease or disorder.

As used herein, the terms “administration of” and “administering a”compound should be understood to mean providing a compound of theinvention, pharmaceutical composition comprising a compound or a prodrugof a compound of the invention to an individual in need thereof. It isrecognized that one skilled in the non-limiting art can treat a patientpresently afflicted with related diseases or disorders or byprophylactically treat a patient afflicted with the diseases ordisorders with an effective amount of the compound of the presentinvention.

The term “composition” as used herein is intended to encompass a productcomprising the specified ingredients in the specified amounts, as wellas any product which results, directly or indirectly, from combinationsof the specified ingredients in the specified amounts. Such term inrelation to pharmaceutical composition, is intended to encompass aproduct comprising the active ingredient(s) and the inert ingredient(s)that make up the carrier, as well as any product which results, directlyor indirectly, from a combination, complexation or aggregation of anytwo or more of the ingredients, or from the other types of reactions orinteractions such as to cause the dissociation of one or more of theingredients. Accordingly, the pharmaceutical compositions of the presentinvention encompass any composition made by mixing a compound of thepresent invention and a pharmaceutically acceptable carrier.

Additional Chemical Descriptions

Any formula given herein is intended to represent compounds havingstructures depicted by the structural formula as well as certainvariations or forms. For example, compounds of any formula given hereinmay have asymmetric or chiral centers and therefore exist in differentstereoisomeric forms. All stereoisomers, including optical isomers,enantiomers, and diastereomers, of the compounds of the general formula,and mixtures thereof, are considered to fall within the scope of theformula. Furthermore, certain structures may exist as geometric isomers(i.e., cis and trans isomers), as tautomers, or as atropisomers. Allsuch isomeric forms, and mixtures thereof, are contemplated herein aspart of the present invention. Thus, any formula given herein isintended to represent a racemate, one or more enantiomeric forms, one ormore diastereomeric forms, one or more tautomeric or atropisomericforms, and mixtures thereof.

“Stereoisomer” refers to compounds which have identical chemicalconstitution, but differ with regard to the arrangement of the atoms orgroups in space. Stereoisomers include enantiomer, diastereomers,conformer (rotamer), geometric (cis/trans) isomer, atropisomer etc.

“Chiral” refers to molecules which have the property ofnon-superimposability of the mirror image partner, while the term“achiral” refers to molecules which are superimposable on their mirrorimage partner.

“Enantiomers” refers to two stereoisomers of a compound which arenon-superimposable mirror images of one another.

“Diastereomer” refers to a stereoisomer with two or more centers ofchirality and whose molecules are not mirror images of one another.Diastereomers have different physical properties, e.g., melting points,boiling points, spectral properties or biological activities. A mixtureof diastereomers may be separated under high resolution analyticalprocedures such as electrophoresis and chromatography such as HPLC.

Stereochemical definitions and conventions used herein generally followS. P. Parker, Ed., McGraw-Hill Dictionary of Chemical Terms (1984)McGraw-Hill Book Company, New York; and Eliel, E. and Wilen, S.,“Stereochemistry of Organic Compounds”, John Wiley & Sons, Inc., NewYork, 1994.

Many organic compounds exist in optically active forms, i.e., they havethe ability to rotate the plane of polarized light. In describing anoptically active compound, the prefixes D and L, or R and S, are used todenote the absolute configuration of the molecule about its chiralcenter(s). The prefixes d and l or (+) and (−) are employed to designatethe sign of rotation of plane-polarized light by the compound, with (−)or l meaning that the compound is levorotatory. A compound prefixed with(+) or d is dextrorotatory. A specific stereoisomer may be referred toas an enantiomer, and a mixture of such stereoisomers is called anenantiomeric mixture. A 50:50 mixture of enantiomers is referred to as aracemic mixture or a racemate, which may occur where there has been nostereoselection or stereospecificity in a chemical reaction or process.

Any asymmetric atom (e.g., carbon or the like) of the compound(s)disclosed herein can be in racemic or enantiomerically enriched, forexample the (R)-, (S)- or (R, S)-configuration. In certain embodiments,each asymmetric atom has at least 50% enantiomeric excess, at least 60%enantiomeric excess, at least 70% enantiomeric excess, at least 80%enantiomeric excess, at least 90% enantiomeric excess, at least 95%enantiomeric excess, or at least 99% enantiomeric excess in the (R)- or(S)-configuration.

Depending on the choice of the starting materials and procedures, thecompounds can be present in the form of one of the possiblestereoisomers or as mixtures thereof, such as racemates anddiastereoisomer mixtures, depending on the number of asymmetric carbonatoms. Optically active (R)- and (S)-isomers may be prepared usingchiral synthons or chiral reagents, or resolved using conventionaltechniques. If the compound contains a double bond, the substituent maybe E or Z configuration. If the compound contains a disubstitutedcycloalkyl, a cycloalkyl substituent may have a cis- ortrans-configuration relative to another substituent of the samecycloalkyl frame.

Any resulting mixtures of stereoisomers can be separated on the basis ofthe physicochemical differences of the constituents, into the pure orsubstantially pure geometric isomers, enantiomers, diastereomers, forexample, by chromatography and/or fractional crystallization. Anyresulting racemates of final products or intermediates can be resolvedinto the optical antipodes by methods known to those skilled in the art,e.g., by separation of the diastereomeric salts thereof. Racemicproducts can also be resolved by chiral chromatography, e.g., highperformance liquid chromatography (HPLC) using a chiral adsorbent.Preferred enantiomers can also be prepared by asymmetric syntheses. See,for example, Jacques, et al., Enantiomers, Racemates and Resolutions(Wiley Interscience, New York, 1981); Principles of Asymmetric Synthesis(2nd Ed. Robert E. Gawley, Jeffrey Aubé, Elsevier, Oxford, U K, 2012);Eliel, E. L. Stereochemistry of Carbon Compounds (McGraw-Hill, N Y,1962); Wilen, S. H. Tables of Resolving Agents and Optical Resolutionsp. 268 (E. L. Eliel, Ed., Univ. of Notre Dame Press, Notre Dame, Ind.1972); Chiral Separation Techniques: A Practical Approach (Subramanian,G. Ed., Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2007).

Diastereomeric mixtures may be separated into their individualdiastereomers on the basis of their physical chemical differences bymethods well known to those skilled in the art, such as, for example, bychromatography and/or fractional crystallization. Enantiomers may beseparated by converting the enantiomeric mixture into a diastereomericmixture by reaction with an appropriate optically active compound (e.g.,chiral auxiliary such as a chiral alcohol or Mosher's acid chloride, orformation of a mixture of diastereomeric salts), separating thediastereomers and converting (e.g., hydrolyzing or de-salting) theindividual diastereomers to the corresponding pure enantiomers.Enantiomers may also be separated by use of chiral HPLC column.

The compounds of the invention can form pharmaceutically acceptablesalts, which are also within the scope of this invention. A“pharmaceutically acceptable salt” refers to a salt of a free acid orbase of a compound of Formula (I)a or (I)b that is non-toxic, isphysiologically tolerable, is compatible with the pharmaceuticalcomposition in which it is formulated, and is otherwise suitable forformulation and/or administration to a subject. Reference to a compoundherein is understood to include reference to a pharmaceuticallyacceptable salt of said compound unless otherwise indicated.

Compound salts include acidic salts formed with inorganic and/or organicacids, as well as basic salts formed with inorganic and/or organicbases. In addition, where a given compound contains both a basic moiety,such as, but not limited to, a pyridine or imidazole, and an acidicmoiety, such as, but not limited to, a carboxylic acid, one of skill inthe art will recognize that the compound may exist as a zwitterion(“inner salt”); such salts are included within the term “salt” as usedherein. Salts of the compounds of the invention may be prepared, forexample, by reacting a compound with an amount of a suitable acid orbase, such as an equivalent amount, in a medium such as one in which thesalt precipitates or in an aqueous medium followed by lyophilization.

Exemplary salts include, but are not limited, to sulfate, citrate,acetate, oxalate, chloride, bromide, iodide, nitrate, bisulfate,phosphate, acid phosphate, isonicotinate, lactate, salicylate, acidcitrate, tartrate, oleate, tannate, pantothenate, bitartrate, ascorbate,succinate, maleate, gentisinate, fumarate, gluconate, glucuronate,saccharate, formate, benzoate, glutamate, methanesulfonate (“mesylate”),ethanesulfonate, benzenesulfonate, p-toluenesulfonate, and pamoate(i.e., 1,1′-methylene-bis(2-hydroxy-3-naphthoate)) salts. Apharmaceutically acceptable salt may involve the inclusion of anothermolecule such as an acetate ion, a succinate ion or other counterion.The counterion may be any organic or inorganic moiety that stabilizesthe charge on the parent compound. Furthermore, a pharmaceuticallyacceptable salt may have more than one charged atom in its structure.Instances where multiple charged atoms are part of the pharmaceuticallyacceptable salt can have multiple counterions. Hence, a pharmaceuticallyacceptable salt can have one or more charged atoms and/or one or morecounter ion.

Exemplary acid addition salts include acetates, ascorbates, benzoates,benzenesulfonates, bisulfates, borates, butyrates, citrates,camphorates, camphorsulfonates, fumarates, hydrochlorides,hydrobromides, hydroiodides, lactates, maleates, methanesulfonates,naphthalenesulfonates, nitrates, oxalates, phosphates, propionates,salicylates, succinates, sulfates, tartarates, thiocyanates,toluenesulfonates (also known as tosylates,) and the like.

Exemplary basic salts include ammonium salts, alkali metal salts such assodium, lithium, and potassium salts, alkaline earth metal salts such ascalcium and magnesium salts, salts with organic bases (for example,organic amines) such as dicyclohexylamines, tert-butyl amines, and saltswith amino acids such as arginine, lysine and the like. Basicnitrogen-containing groups may be quarternized with agents such as loweralkyl halides (e.g., methyl, ethyl, and butyl chlorides, bromides andiodides), dialkyl sulfates (e.g., dimethyl, diethyl, and dibutylsulfates), long chain halides (e.g., decyl, lauryl, and stearylchlorides, bromides and iodides), aralkyl halides (e.g., benzyl andphenethyl bromides), and others.

Additionally, acids and bases which are generally considered suitablefor the formation of pharmaceutically useful salts from pharmaceuticalcompounds are discussed, for example, by P. Stahl et al, Camille G.(eds.) Handbook of Pharmaceutical Salts. Properties, Selection and Use.(2002) Zurich: Wiley-VCH; S. Berge et al, Journal of PharmaceuticalSciences (1977) 66(1) 1-19; P. Gould, International J. of Pharmaceutics(1986) 33 201-217; Anderson et al, The Practice of Medicinal Chemistry(1996), Academic Press, New York; and in The Orange Book (Food & DrugAdministration, MD, available from FDA). These disclosures areincorporated herein by reference thereto.

Additionally, any compound described herein is intended to refer also toany unsolvated form, or a hydrate, solvate, or polymorph of such acompound, and mixtures thereof, even if such forms are not listedexplicitly. “Solvate” means a physical association of a compound of theinvention with one or more solvent molecules. This physical associationinvolves varying degrees of ionic and covalent bonding, includinghydrogen bonding. In certain instances, the solvate will be capable ofisolation, for example when one or more solvent molecules areincorporated in the crystal lattice of a crystalline solid. “Solvate”encompasses both solution-phase and isolatable solvates. Suitablesolvates include those formed with pharmaceutically acceptable solventssuch as water, ethanol, and the like. In some embodiments, the solventis water and the solvates are hydrates.

One or more compounds of the invention may optionally be converted to asolvate. Methods for the preparation of solvates are generally known.Thus, for example, M. Caira et al., J. Pharmaceutical Sci., 93(3),601-611 (2004), describes the preparation of the solvates of theantifungal fluconazole in ethyl acetate as well as from water. Similarpreparations of solvates, hemisolvate, hydrates, and the like aredescribed by E. C. van Tonder et al, AAPS PharmSciTech., 5(1), article12 (2004); and A. L. Bingham et al, Chem. Commun., 603-604 (2001). Atypical, non-limiting process involves dissolving the compound of theinvention in a suitable amount of the solvent (organic solvent or wateror a mixture thereof) at a higher than ambient temperature, and coolingthe solution at a rate sufficient to form crystals which are thenisolated by standard methods. Analytical techniques such as, forexample, infrared spectroscopy, show the presence of the solvent (orwater) in the crystals as a solvate (or hydrate).

The present invention also relates to pharmaceutically activemetabolites of compounds of Formula (I)a or (I)b, and uses of suchmetabolites in the methods of the invention. A “pharmaceutically activemetabolite” means a pharmacologically active product of metabolism inthe body of a compound of Formula (I)a or (I)b or salt thereof. Activemetabolites of a compound may be determined using routine techniquesknown or available in the art. See, e.g., Bertolini et al., J Med. Chem.1997, 40, 2011-2016; Shan et al., J Pharm. Sci. 1997, 86 (7), 765-767;Bagshawe, Drug Dev. Res. 1995, 34, 220-230; Bodor, Adv. Drug Res. 1984,13, 255-331; Bundgaard, Design of Prodrugs (Elsevier Press, 1985); andLarsen, Design and Application of Prodrugs, Drug Design and Development(Krogsgaard-Larsen et al., eds., Harwood Academic Publishers, 1991).

Any formula given herein is also intended to represent unlabeled formsas well as isotopically labeled forms of the compounds. Isotopicallylabeled compounds have structures depicted by the formulas given hereinexcept that one or more atoms are replaced by an atom having a selectedatomic mass or mass number. Examples of isotopes that can beincorporated into compounds of the invention include isotopes ofhydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, andiodine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S,¹⁸F, ³⁶Cl, and ¹²⁵I, respectively. Such isotopically labelled compoundsare useful in metabolic studies (for example with ¹⁴C), reaction kineticstudies (with, for example ²H or ³H), detection or imaging techniques[such as positron emission tomography (PET) or single-photon emissioncomputed tomography (SPECT) including drug or substrate tissuedistribution assays, or in radioactive treatment of patients. Inparticular, an ¹⁸F or ¹¹C labeled compound may be particularly suitablefor PET or SPECT studies. Further, substitution with heavier isotopessuch as deuterium (i.e., ²H) may afford certain therapeutic advantagesresulting from greater metabolic stability, for example increased invivo half-life or reduced dosage requirements. Isotopically labeledcompounds of this invention can generally be prepared by carrying outthe procedures disclosed in the schemes or in the examples andpreparations described below by substituting a readily availableisotopically labeled reagent for a non-isotopically labeled reagent.

The use of the terms “salt”, “solvate”, “polymorph”, and the like, withrespect to the compounds described herein is intended to apply equallyto the salt, solvate, and polymorph forms of enantiomers, stereoisomers,rotamers, tautomers, atropisomers, and racemates of the compounds of theinvention.

Abbreviation:

EA Ethyl acetate

DCM Dichloromethane

THF Tetrahydrofuran

TBAF Tetrabutylammonium Fluoride

PE Petroleum Ether

i-PrOH Isopropanol

PivCl Pivaloyl chloride

TEA Triethylamine

DIEA N-Ethyldiisopropylamine

n-BuLi n-Butyllithium

(Boc)₂O Di-tert-butyl dicarbonate

HMDS Hexamethyldisilazide

BnBr Benzyl bromide

HATU O-(7-azabenzotriazol-1-yl)uronium hexafluoro-phosphate

4-AT (2,2,6,6-Tetramethyl-1-oxy-4-piperidinyl)amine

MTBE Methyl tert-butyl ether

KHMDS Potassium bis(trimethylsilyl)amide

TFA Trifluoracetic acid

T₃P 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphorinane-2,4,6-trioxide

DIADD isopropyl azodicarboxylate

m-CPBA m-Chloroperbenzoic acid

CbzCl Benzyl Chloroformate

Cbz Carbobenzyl

Fmoc 9-Fluorenylmethoxycarbonyl

Boc tert-butyloxy carbonyl

Bn Benzyl

DMFN N′-dimethylformamide

DMAP 4-(dimethylamino)pyridine

DMSO Dimethyl sulphoxide

DBU 1,8-Diazabicyclo[5.4.0]undec-7-ene

CAN ammonium ceric nitrate

HPLC High performance liquid chromatography

J coupling constant (in NMR)

Min minute(s)

H hour(s)

NMR nuclear magnetic resonance

Prep preparative

t-Bu tert-butyl

iPr isopropyl

TLC thin-layer chromatography

Ala Alanine

Leu Arginine

Ile Isoleucine

Phe Phenylalanine

Met Methionine

Pro Proline

Gly Glycine

Ser Serine

Thr Threonine

Cys Cysteine

Tyr Tyrosine

Asn Asparagine

Gln Glutamine

His Histidine

Lys Lysine

Arg Arginine

Asp Aspartic acid

Glu Glutamic acid

DESCRIPTION OF COMPOUNDS OF THE INVENTION

The present invention relates to particular molecules andpharmaceutically acceptable salts or isomers thereof. The inventionfurther relates to molecules which are useful in modulatingdysfunctional glutamate transmission and pharmaceutically acceptablesalts, solvates, esters, or isomers thereof.

The invention is directed to compounds as described herein andpharmaceutically acceptable salts, solvates, esters, or isomers thereof,and pharmaceutical compositions comprising one or more compounds asdescribed herein and pharmaceutically acceptable salts or isomersthereof. One aspect of this invention is the provision of compounds,compositions, kits, and antidotes for modulating glutamate transmissionin mammals having a compound of Formula (I)a or (I)b, pharmaceuticallyacceptable salts thereof, and individual enantiomers and diastereomersthereof.

Wherein z is 0 or 1;

L is absent, or selected from a group consisting of: C1-C10 alkyl,C1-C10 alkoxyl, cycloalkyl, C1-C10 alkylcycloalkyl, heterocycloalkyl,C1-C10 alkylheterocycloalkyl, aryl, C1-C10 alkylaryl, heteroaryl, andC1-C10 alkylheteroaryl, wherein said cycloalkyl, or heterocycloalkyl hasabout 3 to about 7 ring carbons, and said aryl or heteroaryl has about 5to about 10 ring carbons;

Q is selected from a group consisting of:

wherein n is an integer selected from 0 to 10;

-   -   R₁ or R₂ is H or CH₃;    -   R₃ or R₄ is H or C1-C5alkyl;    -   W is absent, O or S; and    -   i) when W is absent, R₃ and R₄ can, optionally, together form        the following structure:

-   -   ii) when W is O, OR₃ and OR₄ can, optionally, together form the        following structure:

PEP is a moiety having the following peptidyl structure:

wherein a * mark denotes a chiral center that can be either in an (S) or(R) configuration and m is an integer selected from 0 to 10;

X₁ is selected from a group consisting of H, —(C═O)—O-Rm, —(SO)—O-Rm,—(SO₂)—O-Rm, —(SO₂)—N-(Rm)₂, and —(C═O)—N-(Rm)₂, where Rm is C1-C6alkyl, C1-C6 alkoxyl, C1-C6 alkenyl, C1-C6 haloalkyl, cycloalkyl, C1-C6alkylcycloalkyl, heterocycloalkyl, C1-C6 alkylheterocycloalkyl, aryl,C1-C6 alkylaryl, heteroaryl, and C1-C6 alkylheteroaryl, wherein saidcycloalkyl, or heterocycloalkyl has about 3 to about 7 ring carbons, andsaid aryl or heteroaryl has about 5 to about 10 ring carbons;

X₂, X₃ or X₄ is selected from a group consisting of C1-C10 alkyl, C1-C10alkenyl, aryl, C1-C6 alkylaryl, heteroaryl, C1-C6 alkylheteroaryl,wherein said aryl or heteroaryl having from 5 to 6 ring carbons;

A is absent, or selected from a group consisting of: Ala, Leu, Ile, Phe,Met, Pro, Gly, Ser, Thr, Cys, Tyr, Asn, Gln, His, Lys, Arg, Asp, Glu,and Val, each of which can be in either a D or L configuration; whereinthe amino residue is either unprotected, or protected by a protectinggroup selected from a group consisting of Cbz, and Fmoc;

G is absent, or selected from a group consisting of: —O—, —S—, —NH—;—NH—(C═O)—O—, —O—(C═O)—NH—, —NH—(C═O)—NH—, —NHSO₂—, —SO—, and —SO₂—.

In some embodiments, in which compounds have the general Formula (I)a or(I)b, wherein L is a straight or branched chain alkyl having about 1 toabout 10 carbon atoms.

In some embodiments, in which compounds have the general Formula (I)a or(I)b, wherein L is a substituted or unsubstituted mono- or bicyclic arylhaving about 5 to about 10 ring carbon atoms, or a C1-C10 alkylarylhaving about 5 to about 10 ring carbon atoms.

In some embodiments, in which compounds have the general Formula (I)a or(I)b, wherein L is a substituted or unsubstituted mono- or bicyclicheteroaryl having about 5 to about 10 carbon or hetero ring atoms, or aC1-C10 alkylaryl having about 5 to about 10 ring carbon or hetero ringatoms, wherein hetero atoms include O, N and S; and preferably, L is asubstituted or unsubstituted pyridine.

In other embodiments, there is the provision of compounds having thegeneral Formula (I)a or (I)b, wherein G is absent, or is, preferably,—NHC═O—, —NH(C═O)—O— or —NHSO₂—.

In still other embodiments, there is the provision of compounds havingthe general Formula (I)a or (I)b, wherein W is absent, O or S;

In yet still other embodiments, in which compounds have the generalFormula (I)a or (I)b, wherein PEP is preferably

wherein a * mark denotes a chiral center that can be either in an (S) or(R) configuration;

X₁ is hydrogen, or selected from the group consisting of —(C═O)—O-Rm,—(SO)—O-Rm, —(SO₂)—O-Rm, —(SO₂)—N-(Rm)₂, and —(C═O)—N-(Rm)₂, where Rm isC1-C6 alkyl, C1-C6 alkoxyl, C1-C6 alkenyl, C1-C6 haloalkyl, cycloalkyl,C1-C6 alkylcycloalkyl, heterocycloalkyl, C1-C6 alkylheterocycloalkyl,aryl, C1-C6 alkylaryl, heteroaryl, and C1-C6 alkylheteroaryl, whereinsaid cycloalkyl, or heterocycloalkyl has about 3 to about 7 ringcarbons, and said aryl or heteroaryl has about 5 to about 10 ringcarbons;

X₂, X₃ or X₄ is selected from a group consisting of C1-C10 alkyl, C1-C10alkenyl, aryl, C1-C6 alkylaryl, heteroaryl, C1-C6 alkylheteroaryl,wherein said aryl or heteroaryl having from 5 to 6 ring carbons;

A is absent, or selected from a group consisting of: Ala, Leu, Ile, Phe,Met, Pro, Gly, Ser, Thr, Cys, Tyr, Asn, Gln, His, Lys, Arg, Asp, Glu,and Val, each of which can be in either a D or L configuration; whereinthe amino residue is either unprotected, or protected by a protectinggroup selected from a group consisting of Cbz and Fmoc.

Another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is,preferably, absent or is Valine.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, X₁ is,preferably, absent, or selected from a group consisting of: Et-O—(C═O)—,i-Pr—O—(C═O)—, t-Bu-O—(C═O)— or cyclopropyl-CH₂—O—(C═O)—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, X₂ is,preferably, selected from a group consisting of: i-Propyl-CH₂—,cyclopropyl-CH₂—, cyclopentyl-CH₂— or Admantyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, X₃ is,preferably, selected from a group consisting of: Ph-CH₂— or Pyr-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, X₄ is,preferably, selected from a group consisting of: i-Propyl-CH₂—,cyclopropyl-CH₂— or cyclopentyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is absent, X₁is t-Bu-O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is absent, X₁is cyclopropyl-CH₂—O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is absent, X₁is ethyl-CH₂—O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is absent, X₁is t-Bu-O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ iscyclopropyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is absent, X₁is t-Bu-O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ iscyclopentyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is absent, X₁is t-Bu-O—(C═O)—, X₂ is Admantyl-CH₂—; X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is valine, X₁is t-Bu-O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is valine, X₁is cyclopropyl-CH₂—O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is valine, X₁is cyclopropyl-CH₂—O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ iscyclopropyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is valine, X₁is cyclopropyl-CH₂—O—(C═O)—, X₂ is i-Propyl-CH₂—, X₃ is Ph-CH₂—, X₄ iscyclopentyl-CH₂—.

Yet another embodiment of the invention is the provision of a compound,wherein the various moieties are independently selected, A is valine, X₁is t-Bu-O—(C═O)—, X₂ is Admantyl-CH₂—; X₃ is Ph-CH₂—, X₄ isi-Propyl-CH₂—.

In certain embodiments, the compound of Formula (I)a or (I)b is furtherillustrated by the following compound group consisting of:

pharmaceutically acceptable salts thereof.

An aspect of the present invention concerns compounds disclosed herein.

An aspect of the present invention concerns compounds which are or canbe modulators of ferroptosis.

An aspect of the present invention concerns the use of compoundsdisclosed herein for the preparation of a medicament used in thetreatment, prevention, inhibition or elimination of tumors.

An aspect of the present invention concerns the use of compoundsdisclosed herein as a modulator of ferroptosis for the preparation of amedicament used in the treatment, prevention, inhibition or eliminationof a disorder or disease or medical condition in a patient by modulatingferroptosis in said patient.

The present invention also describes one or more methods of synthesizingthe compounds of the present invention.

The invention also describes one or more uses of the compounds of thepresent invention.

The invention also describes one or more uses of the compounds of thepresent invention with an adjunctive agent.

The present invention also describes one or more methods of preparingvarious pharmaceutical compositions comprising the compounds of thepresent invention.

The invention also describes one or more uses of the variouspharmaceutical compositions of the present invention for the preparationof a medicament used in the treatment, prevention, inhibition orelimination of a disorder or disease or medical condition in a patientby modulating ferroptosis in said patient.

Pharmaceutical Composition of the Compound of the Invention andPreparations and Administration

The present invention provides a pharmaceutical composition comprisingcompounds of the present invention, e.g., example compounds. Accordingto the specific examples of the present invention, the pharmaceuticalcomposition can further comprise pharmaceutically acceptable excipient,carrier, adjuvant, solvent and a combination thereof.

The present invention provides a method of treating, preventing orameliorating a disease or disorder, comprising administrating a safe andeffective amount of a pharmaceutical composition containing compounds ofthe invention with, optionally, one or more adjunctive therapeuticactive agents.

The amount of the compound of the pharmaceutical composition disclosedherein refers to an amount which can be effectively detected to modulateferroptosis in biological samples and in a patient. The activeingredient may be administered to subjects in need of such treatment indosage that will provide optimal pharmaceutical efficacy, which is notlimited to the desired therapeutic effects, on the route ofadministration, and on the duration of the treatment. The dosage willvary from patient to patient depending upon the nature and severity ofdisease, the patient's weight, special diet then being followed by apatient, concurrent medication, and other factors which those skilled inthe art will recognize.

The actual dosage employed may be varied depending upon the requirementsof the patient and the severity of the condition being treated.Determination of the proper dosage regimen for a particular situation iswithin the skill of the art. For convenience, the total daily dosage maybe divided and administered in portions during the day as required. Theamount and frequency of administration of the compounds of the inventionand/or the pharmaceutically acceptable salts thereof will be regulatedaccording to the judgment of the attending clinician considering suchfactors as age, condition and size of the patient as well as severity ofthe symptoms being treated.

It will also be appreciated that certain of the compounds of the presentinvention can exist in free form for treatment, or where appropriate, asa pharmaceutically acceptable derivative or a prodrug thereof. Apharmaceutically acceptable derivative includes pharmaceuticallyacceptable salts, esters, salts of such esters, or any other adduct orderivative which upon administration to a patient in need thereofprovide, directly or indirectly, a compound as otherwise describedherein, or a therapeutically effective metabolite or residue thereof.

The pharmaceutical compositions of the invention may be prepared andpackaged in bulk form wherein a safe and effective amount of a compoundof Formula (I)a or (I)b disclosed herein can be extracted and then givento the patient, such as with powders or syrups. Generally, dosage levelsof between 0.0001 to 10 mg/kg of body weight daily are administered tothe patient to obtain effective modulation of dysfunctional glutamatetransmission. Alternatively, the pharmaceutical compositions of theinvention may be prepared and packaged in unit dosage form wherein eachphysically discrete unit contains a safe and effective amount of acompound of Formula (I)a or (I)b disclosed herein.

When the pharmaceutical compositions of the present invention alsocontain one or more other active ingredients, in addition to a compoundof the present invention, the weight ratio of the compound of thepresent invention to the second active ingredient may be varied anddepend upon the effective dose of each ingredient. Thus, for example,when a compound of the present invention is combined with another agent,the weight ratio of the compound of the present invention to the otheragent will generally range from about 1000:1 to about 1:1000, such asabout 200:1 to 1:200. Combinations of a compound of the presentinvention and other active ingredients will generally also be within theaforementioned range, but in each case, an effective dose of each activeingredient in the combination should be used.

“Pharmaceutically acceptable excipient” as used herein means apharmaceutically acceptable material, composition or vehicle involved ingiving form or consistency to the pharmaceutical composition. Eachexcipient must be compatible with the other ingredients of thepharmaceutical composition when commingled, such that interactions whichwould substantially reduce the efficacy of the compound of the inventionwhen administered to a patient and would result in pharmaceuticallyunacceptable compositions. In addition, each excipient must of course beof sufficiently high purity to render it pharmaceutically acceptable.

Suitable pharmaceutically acceptable excipients will vary depending uponthe particular dosage form chosen. In addition, suitablepharmaceutically acceptable excipients may be chosen for a particularfunction that they may serve in the composition. For example, certainpharmaceutically acceptable excipients may be chosen for their abilityto facilitate the production of uniform dosage forms. Certainpharmaceutically acceptable excipients may be chosen for their abilityto facilitate the production of stable dosage forms. Certainpharmaceutically acceptable excipients may be chosen for their abilityto facilitate the carrying or transporting the compound of the presentinvention once administered to the patient from one organ, or portion ofthe body, to another organ, or portion of the body. Certainpharmaceutically acceptable excipients may be chosen for their abilityto enhance patient compliance.

Suitable pharmaceutically acceptable excipients include the followingtypes of excipients: diluents, fillers, binders, disintegrants,lubricants, glidants, granulating agents, coating agents, wettingagents, solvents, co-solvents, suspending agents, emulsifiers,sweeteners, flavoring agents, flavor masking agents, coloring agents,anticaking agents, humectants, chelating agents, plasticizers, viscosityincreasing agents, antioxidants, preservatives, stabilizers,surfactants, and buffering agents. The skilled artisan will appreciatethat certain pharmaceutically acceptable excipients may serve more thanone function and may serve alternative functions depending on how muchof the excipient is present in the formulation and what otheringredients are present in the formulation.

Skilled artisans possess the knowledge and skill in the art to enablethem to select suitable pharmaceutically acceptable excipients inappropriate amounts for use in the invention. In addition, there areresources that are available to the skilled artisan that describepharmaceutically acceptable excipients and may be useful in selectingsuitable pharmaceutically acceptable excipients. Examples includeRemington's Pharmaceutical Sciences (Mack Publishing Company), TheHandbook of Pharmaceutical Additives (Gower Publishing Limited), and TheHandbook of Pharmaceutical Excipients (the American PharmaceuticalAssociation and the Pharmaceutical Press).

In Remington: The Science and Practice of Pharmacy, 21st edition, 2005,ed. D. B. Troy, Lippincott Williams & Wilkins, Philadelphia, andEncyclopedia of Pharmaceutical Technology, eds. J. Swarbrick and J. C.Boylan, 1988-1999, Marcel Dekker, New York, the contents of each ofwhich is incorporated by reference herein, are disclosed variouscarriers used in formulating pharmaceutically acceptable compositionsand known techniques for the preparation thereof. Except insofar as anyconventional carrier medium is incompatible with the compounds of theinvention, such as by producing any undesirable biological effect orotherwise interacting in a deleterious manner with any othercomponent(s) of the pharmaceutically acceptable composition, its use iscontemplated to be within the scope of this invention.

The pharmaceutical compositions of the invention are prepared usingtechniques and methods known to those skilled in the art. Some of themethods commonly used in the art are described in Remington'sPharmaceutical Sciences (Mack Publishing Company).

Therefore, another aspect of the present invention is related to amethod for preparing a pharmaceutical composition. The pharmaceuticalcomposition contains the compound disclosed herein and pharmaceuticallyacceptable excipient, carrier, adjuvant, vehicle or a combinationthereof, the method comprises mixing various ingredients. Thepharmaceutical composition containing the compound disclosed herein canbe prepared for example at normal ambient temperature and pressure.

The compound of the invention will typically be formulated into a dosageform adapted for administration to the patient by the desired route ofadministration. For example, dosage forms include those adapted for (1)oral administration such as tablets, capsules, caplets, pills, troches,powders, syrups, elixirs, suspensions, solutions, emulsions, sachets,and cachets; (2) parenteral administration such as sterile solutions,suspensions, and powders for reconstitution; (3) transdermaladministration such as transdermal patches; (4) rectal administrationsuch as suppositories; (5) inhalation such as aerosols, solutions, anddry powders; and (6) topical administration such as creams, ointments,lotions, solutions, pastes, sprays, foams, and gels.

The pharmaceutical compositions provided herein may be provided ascompressed tablets, tablet triturates, chewable lozenges, rapidlydissolving tablets, multiple compressed tablets, or enteric-coatingtablets, sugar-coated, or film-coated tablets. Enteric-coated tabletsare compressed tablets coated with substances that resist the action ofstomach acid but dissolve or disintegrate in the intestine, thusprotecting the active ingredients from the acidic environment of thestomach. Enteric-coatings include, but are not limited to, fatty acids,fats, phenylsalicylate, waxes, shellac, ammoniated shellac, andcellulose acetate phthalates. Sugar-coated tablets are compressedtablets surrounded by a sugar coating, which may be beneficial incovering up objectionable tastes or odors and in protecting the tabletsfrom oxidation. Film-coated tablets are compressed tablets that arecovered with a thin layer or film of a water-soluble material. Filmcoatings include, but are not limited to, hydroxyethylcellulose, sodiumcarboxymethylcellulose, polyethylene glycol 4000, and cellulose acetatephthalate. Film coating imparts the same general characteristics assugar coating. Multiple compressed tablets are compressed tablets madeby more than one compression cycle, including layered tablets, andpress-coated or dry-coated tablets.

The tablet dosage forms may be prepared from the active ingredient inpowdered, crystalline, or granular forms, alone or in combination withone or more carriers or excipients described herein, including binders,disintegrants, controlled-release polymers, lubricants, diluents, and/orcolorants.

Flavoring and sweetening agents are especially useful in the formationof chewable tablets and lozenges.

The pharmaceutical compositions provided herein may be provided as softor hard capsules, which can be made from gelatin, methylcellulose,starch, or calcium alginate. The hard gelatin capsule, also known as thedry-filled capsule (DFC), consists of two sections, one slipping overthe other, thus completely enclosing the active ingredient. The softelastic capsule (SEC) is a soft, globular shell, such as a gelatinshell, which is plasticized by the addition of glycerin, sorbitol, or asimilar polyol. The soft gelatin shells may contain a preservative toprevent the growth of microorganisms. Suitable preservatives are thoseas described herein, including methyl- and propyl-parabens, and ascorbicacid. The liquid, semisolid, and solid dosage forms provided herein maybe encapsulated in a capsule. Suitable liquid and semisolid dosage formsinclude solutions and suspensions in propylene carbonate, vegetableoils, or triglycerides. Capsules containing such solutions can beprepared as described in U.S. Pat. Nos. 4,328,245; 4,409,239; and4,410,545. The capsules may also be coated as known by those of skill inthe art to modify or sustain dissolution of the active ingredient.

The pharmaceutical compositions provided herein may be provided inliquid and semisolid dosage forms, including emulsions, solutions,suspensions, elixirs, and syrups. An emulsion is a two-phase system, inwhich one liquid is dispersed in the form of small globules throughoutanother liquid, which can be oil-in-water or water-in-oil. Emulsions mayinclude a pharmaceutically acceptable non-aqueous liquids or solvent,emulsifying agent, and preservative. Suspensions may include apharmaceutically acceptable suspending agent and preservative. Aqueousalcoholic solutions may include a pharmaceutically acceptable acetal,such as a di(lower alkyl)acetal of a lower alkyl aldehyde, e.g.,acetaldehyde diethyl acetal; and a water-miscible solvent having one ormore hydroxy groups, such as propylene glycol and ethanol. Elixirs areclear, sweetened, and hydroalcoholic solutions. Syrups are concentratedaqueous solutions of a sugar, for example, sucrose, and may also containa preservative. For a liquid dosage form, for example, a solution in apolyethylene glycol may be diluted with a sufficient quantity of apharmaceutically acceptable liquid carrier, e.g., water, to be measuredconveniently for administration.

Other useful liquid and semisolid dosage forms include, but are notlimited to, those containing the active ingredient(s) provided herein,and a dialkylated mono- or poly-alkylene glycol, including,1,2-dimethoxymethane, diglyme, triglyme, tetraglyme, polyethyleneglycol-350-dimethyl ether, polyethylene glycol-550-dimethyl ether,polyethylene glycol-750-dimethyl ether, wherein 350, 550, and 750 referto the approximate average molecular weight of the polyethylene glycol.These formulations may further comprise one or more antioxidants, suchas butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA),propyl gallate, vitamin E, hydroquinone, hydroxycoumarins, ethanolamine,lecithin, cephalin, ascorbic acid, malic acid, sorbitol, phosphoricacid, bisulfite, sodium metabisulfite, thiodipropionic acid and itsesters, and dithiocarbamates.

Where appropriate, dosage unit formulations for oral administration canbe microencapsulated. The formulation can also be prepared to prolong orsustain the release as for example by coating or embedding particulatematerial in polymers, wax, or the like.

The pharmaceutical compositions provided herein for oral administrationmay be also provided in the forms of liposomes, micelles, microspheres,or nanosystems. Micellar dosage forms can be prepared as described inU.S. Pat. No. 6,350,458.

The pharmaceutical compositions provided herein may be provided asnon-effervescent or effervescent, granules and powders, to bereconstituted into a liquid dosage form. Pharmaceutically acceptablecarriers and excipients used in the non-effervescent granules or powdersmay include diluents, sweeteners, and wetting agents. Pharmaceuticallyacceptable carriers and excipients used in the effervescent granules orpowders may include organic acids and a source of carbon dioxide.

Coloring and flavoring agents can be used in all above dosage forms.

The compounds disclosed herein can also be coupled to soluble polymersas targeted medicament carriers. Such polymers may encompasspolyvinylpyrrolidone, pyran copolymer,polyhydroxypropylmethacrylamidophenol, polyhydroxyethylaspartamidophenolor polyethylene oxide polylysine, substituted by palmitoyl radicals. Thecompounds may furthermore be coupled to a class of biodegradablepolymers which are suitable for achieving controlled release of amedicament, for example polylactic acid, poly-epsilon-caprolactone,polyhydroxybutyric acid, polyorthoesters, polyacetals,polydihydroxypyrans, polycyanoacrylates and crosslinked or amphipathicblock copolymers of hydrogels.

The pharmaceutical compositions provided herein may be formulated asimmediate or modified release dosage forms, including delayed-,sustained, pulsed-, controlled, targeted-, and programmed-release forms.

The pharmaceutical compositions provided herein may be co-formulatedwith other active ingredients which do not impair the desiredtherapeutic action, or with substances that supplement the desiredaction.

The pharmaceutical compositions provided herein may be administeredparenterally by injection, infusion, or implantation, for local orsystemic administration. Parenteral administration, as used herein,include intravenous, intraarterial, intraperitoneal, intrathecal,intraventricular, intraurethral, intrasternal, intracranial,intramuscular, intrasynovial, and subcutaneous administration.

The pharmaceutical compositions provided herein may be formulated in anydosage forms that are suitable for parenteral administration, includingsolutions, suspensions, emulsions, micelles, liposomes, microspheres,nanosystems, and solid forms suitable for solutions or suspensions inliquid prior to injection. Such dosage forms can be prepared accordingto conventional methods known to those skilled in the art ofpharmaceutical science (see, Remington: The Science and Practice ofPharmacy, supra).

The pharmaceutical compositions intended for parenteral administrationmay include one or more pharmaceutically acceptable carriers andexcipients, including, but not limited to, aqueous vehicles,water-miscible vehicles, non-aqueous vehicles, antimicrobial agents orpreservatives against the growth of microorganisms, stabilizers,solubility enhancers, isotonic agents, buffering agents, antioxidants,local anesthetics, suspending and dispersing agents, wetting oremulsifying agents, complexing agents, sequestering or chelating agents,cryoprotectants, lyoprotectants, thickening agents, pH adjusting agents,and inert gases.

Suitable aqueous vehicles include, but are not limited to, water,saline, physiological saline or phosphate buffered saline (PBS), sodiumchloride injection, Ringers injection, isotonic dextrose injection,sterile water injection, dextrose and lactated Ringers injection.Non-aqueous vehicles include, but are not limited to, fixed oils ofvegetable origin, castor oil, corn oil, cottonseed oil, olive oil,peanut oil, peppermint oil, safflower oil, sesame oil, soybean oil,hydrogenated vegetable oils, hydrogenated soybean oil, and medium-chaintriglycerides of coconut oil, and palm seed oil. Water-miscible vehiclesinclude, but are not limited to, ethanol, 1,3-butanediol, liquidpolyethylene glycol (e.g., polyethylene glycol 300 and polyethyleneglycol 400), propylene glycol, glycerin, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and dimethyl sulfoxide.

Suitable antimicrobial agents or preservatives include, but are notlimited to, phenols, cresols, mercurials, benzyl alcohol, chlorobutanol,methyl and propyl p-hydroxybenzoates, thimerosal, benzalkonium chloride(e.g., benzethonium chloride), methyl- and propyl-parabens, and sorbicacid. Suitable isotonic agents include, but are not limited to, sodiumchloride, glycerin, and dextrose. Suitable buffering agents include, butare not limited to, phosphate and citrate. Suitable antioxidants arethose as described herein, including bisulfite and sodium metabisulfite.Suitable local anesthetics include, but are not limited to, procainehydrochloride. Suitable suspending and dispersing agents are those asdescribed herein, including sodium carboxymethylcelluose, hydroxypropylmethylcellulose, and polyvinylpyrrolidone. Suitable emulsifying agentsinclude those described herein, including polyoxyethylene sorbitanmonolaurate, polyoxyethylene sorbitan monooleate 80 and triethanolamineoleate. Suitable sequestering or chelating agents include, but are notlimited to EDTA. Suitable pH adjusting agents include, but are notlimited to, sodium hydroxide, hydrochloric acid, citric acid, and lacticacid. Suitable complexing agents include, but are not limited to,cyclodextrins, including α-cyclodextrin, β-cyclodextrin,hydroxypropyl-β-cyclodextrin, sulfobutylether-β-cyclodextrin, andsulfobutylether 7-β-cyclodextrin (CAPTISOL®, CyDex, Lenexa, Kans.).

The pharmaceutical compositions provided herein may be formulated forsingle or multiple dosage administration. The single dosage formulationsare packaged in an ampoule, a vial, or a syringe. The multiple dosageparenteral formulations must contain an antimicrobial agent atbacteriostatic or fungistatic concentrations. All parenteralformulations must be sterile, as known and practiced in the art.

In one embodiment, the pharmaceutical compositions are provided asready-to-use sterile solutions. In another embodiment, thepharmaceutical compositions are provided as sterile dry solubleproducts, including lyophilized powders and hypodermic tablets, to bereconstituted with a sterile vehicle prior to use. In yet anotherembodiment, the pharmaceutical compositions are provided as ready-to-usesterile suspensions. In yet another embodiment, the pharmaceuticalcompositions are provided as sterile dry insoluble products to bereconstituted with a vehicle prior to use. In still another embodiment,the pharmaceutical compositions are provided as ready-to-use sterileemulsions.

The pharmaceutical compositions may be formulated as a suspension,solid, semi-solid, or thixotropic liquid, for administration as animplanted depot. In one embodiment, the pharmaceutical compositionsprovided herein are dispersed in a solid inner matrix, which issurrounded by an outer polymeric membrane that is insoluble in bodyfluids but allows the active ingredient in the pharmaceuticalcompositions diffuse through.

Suitable inner matrixes include polymethylmethacrylate,polybutyl-methacrylate, plasticized or unplasticized polyvinylchloride,plasticized nylon, plasticized polyethylene terephthalate, naturalrubber, polyisoprene, polyisobutylene, polybutadiene, polyethylene,ethylene-vinyl acetate copolymers, silicone rubbers,polydimethylsiloxanes, silicone carbonate copolymers, hydrophilicpolymers, such as hydrogels of esters of acrylic and methacrylic acid,collagen, cross-linked polyvinyl alcohol, and cross-linked partiallyhydrolyzed polyvinyl acetate.

Suitable outer polymeric membranes include polyethylene, polypropylene,ethylene/propylene copolymers, ethylene/ethyl acrylate copolymers,ethylene/vinyl acetate copolymers, silicone rubbers, polydimethylsiloxanes, neoprene rubber, chlorinated polyethylene, polyvinylchloride,vinyl chloride copolymers with vinyl acetate, vinylidene chloride,ethylene and propylene, ionomer polyethylene terephthalate, butyl rubberepichlorohydrin rubbers, ethylene/vinyl alcohol copolymer,ethylene/vinyl acetate/vinyl alcohol terpolymer, andethylene/vinyloxyethanol copolymer.

In other aspect, the pharmaceutical composition of the invention isprepared to a dosage form adapted for administration to a patient byinhalation, for example as a dry powder, an aerosol, a suspension, or asolution composition. In one embodiment, the invention is directed to adosage form adapted for administration to a patient by inhalation as adry powder. In one embodiment, the invention is directed to a dosageform adapted for administration to a patient by inhalation as a drypowder. Dry powder compositions for delivery to the lung by inhalationtypically comprise a compound disclosed herein or a pharmaceuticallyacceptable salt thereof as a finely divided powder together with one ormore pharmaceutically-acceptable excipients as finely divided powders.Pharmaceutically-acceptable excipients particularly suited for use indry powders are known to those skilled in the art and include lactose,starch, mannitol, and mono-, di-, and polysaccharides. The finelydivided powder may be prepared by, for example, micronisation andmilling. Generally, the size-reduced (e.g. micronised) compound can bedefined by a D₅₀ value of about 1 to about 10 microns (for example asmeasured using laser diffraction).

Aerosols may be formed by suspending or dissolving a compound disclosedherein or a pharmaceutically acceptable salt thereof in a liquifiedpropellant. Suitable propellants include halocarbons, hydrocarbons, andother liquefied gases. Representative propellants include:trichlorofluoromethane (propellant 11), dichlorofluoromethane(propellant 12), dichlorotetrafluoroethane (propellant 114),tetrafluoroethane (HFA-134a), 1,1-difluoroethane (HFA-152a),difluoromethane (HFA-32), pentafluoroethane (HFA-12), heptafluoropropane(HFA-227a), perfluoropropane, perfluorobutane, perfluoropentane, butane,isobutane, and pentane. Aerosols comprising a compound of Formula (I)aor (I)b or a pharmaceutically acceptable salt thereof will typically beadministered to a patient via a metered dose inhaler (MDI). Such devicesare known to those skilled in the art.

The aerosol may contain additional pharmaceutically-acceptableexcipients typically used with MDIs such as surfactants, lubricants,cosolvents and other excipients to improve the physical stability of theformulation, to improve valve performance, to improve solubility, or toimprove taste.

Pharmaceutical compositions adapted for transdermal administration maybe presented as discrete patches intended to remain in intimate contactwith the epidermis of the patient for a prolonged period of time. Forexample, the active ingredient may be delivered from the patch byiontophoresis as generally described in Pharmaceutical Research, 3(6),318 (1986).

Pharmaceutical compositions adapted for topical administration may beformulated as ointments, creams, suspensions, lotions, powders,solutions, pastes, gels, sprays, aerosols or oils. Ointments, creams andgels, may, for example, be formulated with an aqueous or oily base withthe addition of suitable thickening and/or gelling agent and/orsolvents. Such bases may thus, for example, include water and/or an oilsuch as liquid paraffin or a vegetable oil such as arachis oil or castoroil, or a solvent such as polyethylene glycol. Thickening agents andgelling agents which may be used according to the nature of the baseinclude soft paraffin, aluminum stearate, cetostearyl alcohol,polyethylene glycols, woolfat, beeswax, carboxypolymethylene andcellulose derivatives, and/or glyceryl monostearate and/or non-ionicemulsifying agents.

Lotions may be formulated with an aqueous or oily base and will ingeneral also contain one or more emulsifying agents, stabilising agents,dispersing agents, suspending agents or thickening agents.

Powders for external application may be formed with the aid of anysuitable powder base, for example, talc, lactose or starch. Drops may beformulated with an aqueous or non-aqueous base also comprising one ormore dispersing agents, solubilising agents, suspending agents orpreservatives.

Topical preparations may be administered via one or more applicationsper day to the affected area; over skin areas occlusive dressings mayadvantageously be used. Continuous or prolonged delivery may be achievedvia an adhesive reservoir system.

Uses of the Compounds and Compositions of the Invention

Compounds or pharmaceutical compositions of the invention disclosedherein can be used in an amount which can be effectively detected tomodulate ferroptosis in biological samples, or a related disorder ordisease in a subject. Such uses may include in the manufacture of amedicament for treating, preventing, ameliorating or mitigating adisorder or disease in a subject, as well as other medicaments formodulating ferroptosis, and the compounds of this invention havesuperior pharmacokinetic and pharmacodynamic properties, fewer toxicside-effect.

Specifically, the amount of the compound of compositions of the presentinvention may be shown to effectively and detectably modulateferroptosis in biological samples, or a related disorder or disease in asubject. The compounds or pharmaceutical compositions of the inventionmay be used for preventing, treating or alleviating diseases relating toferroptosis in patients.

In one embodiment, the therapies disclosed herein compriseadministrating a safe and effective amount of the compound of theinvention or the pharmaceutical composition containing the compound ofthe invention to patients in need. Each example disclosed hereincomprises the method of treating the diseases above comprisingadministrating a safe and effective amount of the compound of theinvention or the pharmaceutical composition containing the compound ofthe invention to patients in need.

In one embodiment, the compound of the invention or the pharmaceuticalcomposition thereof may be administered by any suitable route ofadministration, including both systemic administration and topicaladministration. Systemic administration includes oral administration,parenteral administration, transdermal administration and rectaladministration. Parenteral administration refers to routes ofadministration other than enteral or transdermal, and is typically byinjection or infusion. Parenteral administration includes intravenous,intramuscular, and subcutaneous injection or infusion. Topicaladministration includes application to the skin as well as intraocular,intravaginal, inhaled and intranasal administration. In one embodiment,the compound of the invention or the pharmaceutical composition thereofmay be administered orally. In another embodiment, the compound of theinvention or the pharmaceutical composition thereof may be administeredby inhalation. In a further embodiment, the compound of the invention orthe pharmaceutical composition thereof may be administered intranasal.

In one embodiment, the compound of the invention or the pharmaceuticalcomposition thereof may be administered once or according to a dosingregimen wherein multiple doses are administered at varying intervals oftime for a given period of time. For example, doses may be administeredone, two, three, or four times per day. In one embodiment, a dose isadministered once per day. In a further embodiment, a dose isadministered twice per day. Doses may be administered until the desiredtherapeutic effect is achieved or indefinitely to maintain the desiredtherapeutic effect. Suitable dosing regimens for the compound of theinvention or the pharmaceutical composition thereof depend on thepharmacokinetic properties of that compound, such as its absorption,distribution, and half-lives of metabolism and elimination, which can bedetermined by the skilled artisan. In addition, suitable dosingregimens, including the duration such regimens are administered, for thecompound of the invention or the pharmaceutical composition thereofdepend on the disorder being treated, the severity of the disorder beingtreated, the age and physical condition of the patient being treated,the medical history of the patient to be treated, the nature ofconcurrent therapy, the desired therapeutic effect, and like factorswithin the knowledge and expertise of the skilled artisan. It will befurther understood by such skilled artisans that suitable dosingregimens may require adjustment given an individual patient's toleranceto the dosing regimen or over time as individual patient needs change.

The compounds of the present invention may be administered eithersimultaneously with, or before or after, one or more other therapeuticagents. The compounds of the present invention may be administeredseparately, by the same or different route of administration, ortogether in the same pharmaceutical composition as the other agents.

The pharmaceutical composition or combination of the present inventioncan be in unit dosage of about 1-1000 mg of active ingredients for asubject of about 50-70 kg, preferably about 1-500 mg or about 1-250 mgor about 1-150 mg or about 0.5-100 mg or about 1-50 mg of activeingredients. The therapeutically effective dosage of a compound, thepharmaceutical composition, or the combinations thereof, is dependent onthe species of the subject, the body weight, age and individualcondition, the disorder or disease or the severity thereof beingtreated. A physician, clinician or veterinarian of ordinary skill canreadily determine the effective amount of each of the active ingredientsnecessary to prevent, treat or inhibit the progress of the disorder ordisease.

The above-cited dosage properties can be correlated with in vitro and invivo tests using advantageously mammals, e.g., mice, rats, dogs,non-human primates, such as monkeys or isolated organs, tissues andpreparations thereof. The compounds of the present invention can beapplied in vitro in the form of solutions, e.g., preferably aqueoussolutions, and in vivo via topically, inhalingly, enterally orparenterally, advantageously intravenously, e.g., as a suspension or inaqueous solution.

In one embodiment, a therapeutically effective dosage of the compounddisclosed herein from about 0.1 mg to about 1,000 mg per day. Thepharmaceutical compositions should provide a dosage of from about 0.1 mgto about 1,000 mg of the compound. In a special embodiment,pharmaceutical dosage unit forms are prepared to provide from about 1 mgto about 1,000 mg, about 10 mg to about 500 mg, about 20 mg to about 200mg, about 25 mg to about 100 mg, or about 30 mg to about 60 mg of theactive ingredient or a combination of essential ingredients per dosageunit form. In a special embodiment, pharmaceutical dosage unit forms areprepared to provide about 1 mg, 5 mg, 10 mg, 20 mg, 25 mg, 50 mg, 100mg, 250 mg, 500 mg, 1000 mg of the active ingredient.

Preferred Embodiment of the Invention General Synthetic Procedures

The following examples are provided so that the invention might be morefully understood. However, it should be understood that theseembodiments merely provide a method of practicing the present invention,and the present invention is not limited to these embodiments.

Generally, the compounds disclosed herein may be prepared by methodsdescribed herein, wherein the substituents are as defined for Formula(I)a or (I)b above, except where further noted. The followingnon-limiting schemes and examples are presented to further exemplify theinvention.

Professionals skilled in the art will recognize that the chemicalreactions described may be readily adapted to prepare a number of othercompounds disclosed herein, and alternative methods for preparing thecompounds disclosed herein are deemed to be within the scope disclosedherein. Those having skill in the art will recognize that the startingmaterials may be varied and additional steps employed to producecompounds encompassed by the present inventions, as demonstrated by thefollowing examples. In some cases, protection of certain reactivefunctionalities may be necessary to achieve some of the abovetransformations. In general, such need for protecting groups, as well asthe conditions necessary to attach and remove such groups, will beapparent to those skilled in the art of organic synthesis. For example,the synthesis of non-exemplified compounds according to the inventionmay be successfully performed by modifications apparent to those skilledin the art, by appropriately protecting interfering groups, by utilizingother suitable reagents known in the art other than those described,and/or by making routine modifications of reaction conditions.Alternatively, the known reaction conditions or the reaction disclosedin the present invention will be recognized as having applicability forpreparing other compounds disclosed here.

In the examples described below, unless otherwise indicated alltemperatures are set forth in degrees Celsius. Reagents were purchasedfrom commercial suppliers such as Aldrich Chemical Company, ArcoChemical Company and Alfa Chemical Company, and were used withoutfurther purification unless otherwise indicated.

Preparation of Compounds

Compounds of the present invention, including salts, esters, hydrates,or solvates thereof, can be prepared using any known organic synthesistechniques and can be synthesized according to any of numerous possiblesynthetic routes.

The reactions for preparing compounds of the present invention can becarried out in suitable solvents, which can be readily selected by oneskilled in the art of organic synthesis. Suitable solvents can besubstantially non-reactive with the starting materials (reactants), theintermediates, or products at the temperatures at which the reactionsare carried out, e.g., temperatures that can range from the solvent'sfreezing temperature to the solvent's boiling temperature. A givenreaction can be carried out in one solvent or a mixture of more than onesolvent. Depending on the particular reaction step, suitable solventsfor a particular reaction step can be selected by a skilled artisan.

Reactions can be monitored according to any suitable method known in theart. For example, product formation can be monitored by spectroscopicmeans, such as nuclear magnetic resonance spectroscopy (e.g., ¹H or¹³C), infrared spectroscopy, spectrophotometry (e.g., UV-visible), massspectrometry, or by chromatographic methods such as high performanceliquid chromatography (HPLC), liquid chromatography-mass spectroscopy(LCMS), or thin layer chromatography (TLC). Compounds can be purified bythose skilled in the art by a variety of methods, including highperformance liquid chromatography (HPLC) (“Preparative LC-MSPurification: Improved Compound Specific Method Optimization” Karl F.Blom, Brian Glass, Richard Sparks, Andrew P. Combs J. Combi. Chem. 2004,6(6), 874-883, which is incorporated herein by reference in itsentirety) and atmospheric pressure column chromatography using silicagel.

Compounds of the present invention can be synthesized using the methodsdescribed below, together with synthetic methods known in the art ofsynthetic organic chemistry, or variations thereon as appreciated bythose skilled in the art. Preferred methods include but are not limitedto those methods described below. Specifically, the compounds of thepresent invention of Formula (I)a or (I)b can be synthesized byfollowing the steps outlined in the exemplary general synthetic schemeslisted below, and the abbreviations for the reactants or for thechemical groups of the reactants included in the synthetic schemes aredefined in the Examples.

The synthesis towards structure A1 can be conducted according to therelevant procedures disclosed in references (1, Journal of the AmericanChemical Society, 2005, 127, 12460-12461; 2, Organic Letter, 2011, 13,2318-2321; Journal of Organic Chemistry, 2010, 75, 941-944), but is notlimited to these disclosed procedures. Sulfonamide derivatives 1condensed with compound 2 at the presence of Cp₂ZrHCl to give theenantiomer compound 3, which is further removed the protecting group andoxidized to acid compound 4. With the help of Evans chiral auxiliary,another chiral center was added onto the compound 4 to furnish structureA1.

The structure A2 is also can be conducted according to the alternativeroute synthesis according to the relevant procedures disclosed inreferences (Journal of Organic Chemistry, 2012, 77, 6358-6364; OrganicProcess Research & Development 2010, 14, 441-458; Journal of OrganicChemistry, 1994, 59, 1139-1148), but is not limited to these disclosedprocedures. Compound 5 with the help of Evans chiral auxiliary, a chiralcenter was added onto the compound 6, which is further oxide to aldehyde7. Compound 7 was condensed with compound 4 via the mechanism of Juliaolefination reaction to give compound 9, which is further oxidized tostructure A2.

The synthesis towards structure B can be conducted according to therelevant procedures disclosed in references (Bulletin of the ChemicalSociety of Japan, 1993, 66, 3113-3115; U.S. Pat. No. 7,528,174B2), butis not limited to these disclosed procedures.

The synthesis towards structure C can be conducted according to therelevant procedures disclosed in references (ACS Central Science, 2016,2 (9), pp 653-659; Journal of Medicinal Chemistry, 1986, 959-971;Journal of Medicinal Chemistry, 1984, 27, 684-691), but is not limitedto these disclosed procedures.

The synthesis towards structure D can be conducted according to therelevant procedures disclosed in references (US2007161573A1;US2009042808A1; Journal of Medicinal Chemistry, 1984, 27, 1351-1354),but is not limited to these disclosed procedures.

The synthesis towards structure E can be conducted according to therelevant procedures disclosed in references (US2007161573A1;US2009042808A1; Journal of the American Chemical Society, 2005, 127,5742-5743; Journal of Organic Chemistry, 2004, 69, 7851-7859), but isnot limited to these disclosed procedures.

The synthesis towards structure F can be conducted according to therelevant procedures disclosed in references (US2007161573A1; Journal ofthe American Chemical Society, 2005, 127, 5742-5743; InternationalJournal of Peptide and Protein Research, 1996; 47, 460-466), but is notlimited to these disclosed procedures.

The synthesis towards structure H can be conducted according to therelevant procedures disclosed in references (US2007161573A1; Journal ofPharmacology and Experimental Therapeutics, 2007, 320, 1050-1060), butis not limited to these disclosed procedures.

Preparation and Characterization of Exemplary Compounds

Compounds encompassed in the present disclosure may be prepared viadifferent schemes. Detailed preparation processes of those exemplarycompounds via various schemes are described below and thecharacterization results are listed as well.

Unless stated otherwise, all reagents were purchased from commercialsuppliers without further purification. Solvent drying by standardmethods was employed when necessary. The plates used for thin-layerchromatography (TLC) were E. Merck silica gel 60F254 (0.24 nm thickness)precoated on aluminum plates, and then visualized under UV light (365 nmand 254 nm) or through staining with a 5% of dodecamolybdophosphoricacid in ethanol and subsequent heating. Column chromatography wasperformed using silica gel (200-400 mesh) from commercial suppliers. ¹HNMR spectra were recorded on an Agilent 400-MR NMR spectrometer (400.00MHz for 1 H) at room temperature. Solvent signal was used as referencefor ¹H NMR (CDCl₃, 7.26 ppm; CD₃OD, 3.31 ppm; DMSO-d6, 2.50 ppm; D₂O,4.79 ppm). The following NMR acronyms and abbreviations were used toexplain the multiplicities: s=singlet, d=doublet, t=triplet, q=quartet,br. s.=broad singlet, dd=double doublet, td=triple doublet, dt=doubletriplet, dq=double quartet, m=multiplet.

EXAMPLES

It should be noted that embodiments of the present invention describedin detail below are exemplary for explaining the present invention only,and not be construed as limiting the present scope of invention.Examples without a specific technology or condition can be implementedaccording to technology or condition in the documentation of the art oraccording to the product instructions. The reagents or instrumentswithout manufacturers are available through conventional purchase. Thosehaving skill in the art will recognize that the starting materials maybe varied and additional steps employed to produce compounds encompassedby the present inventions, as demonstrated by the following examples.

Example 1:tert-Butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-6-(3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propanamido)-1-(isopropylamino)-1-oxohexan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate(I), tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-5-({[3-(4,5-dimnethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)-1-[(propan-2-yl)carbamoyl]pentyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(II) tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-5-[({[1-(4,5-dimethoxy-2-methyl-3,6-dioxocyclohexa-1,4-dien-1-yl)decyl]oxy}carbonyl)amino]-1-[(propan-2-yl)carbamoyl]pentyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(III)

Step 1: Synthesis of (S)-(9H-fluoren-9-yl)methyl tert-butyl(6-(isopropylamino)-6-oxohexane-1,5-diyl)dicarbamate (52)

To a solution of compound 51 (500 mg, 1.07 mmol) and propan-2-amine (76mg, 1.28 mmol) in CH₂Cl₂ (10 mL) at 0° C. was added T₃P (714 mg, 1.28mmol) and DIEA (165 mg, 1.28 mmol). The reaction mixture was allowed towarm to 25° C. and stirred for 16 h. The reaction mixture was quenchedwith saturated aqueous NH₄Cl solution (20 mL), and extracted by EtOAc(3×10 mL). The organic layer was washed with aqueous (5%) NaHCO₃solution, aqueous HCl (10 mL, 1 M), brine solution (3×10 mL), and driedover Na₂SO₄. The residues were concentrated in vacuum to give product 52(480 mg, 88%) as a white foam. MS (ESI): [M+H⁺]=496.2.

Step 2: Synthesis of (S)-(9H-fluoren-9-yl)methyl(5-amino-6-(isopropylamino)-6-oxohexyl)carbamate (53)

A solution of compound 52 (480 mg, 0.94 mmol) in HCl in MeOH (10 mL, 3M) was stirred at 25° C. for 2 h and then the solvents were removed invacuum to give product 53 (384 mg, 100%) as a white foam. MS (ESI):[M+H⁺]=396.1.

Step 3: Synthesis of (S)-tert-butyl2-(((R)-6-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-1-(isopropylamino)-1-oxohexan-2-yl)carbamoyl)pyrrolidine-1-carboxylate(54)

To a solution of compound 53 (384 mg, 0.94 mmol) and(S)-1-(tert-butoxycarbonyl) pyrrolidine-2-carboxylic acid (243 mg,1.1.13 mmol) in CH₂Cl₂ (10 mL) at 0° C. was added T₃P (720 mg, 1.13mmol) and DIEA (146 mg, 1.13 mmol). The reaction mixture was allowed towarm to 25° C. and stirred for 16 h. The reaction mixture was quenchedwith saturated aqueous NH₄Cl solution (10 mL), and extracted by EtOAc(3×10 mL). The organic layer was washed with aqueous (5%) NaHCO₃solution (10 mL), aqueous HCl (2×10 mL, 1 M), saturated aqueous brinesolution (3×10 mL), and dried over Na₂SO₄. The organic layer wasconcentrated in vacuum to give the product 54 (530 mg, 87%) as a whitefoam. MS (ESI): [M+H⁺]=593.4.

Step 4: Synthesis of (9H-fluoren-9-yl)methyl((S)-6-(isopropylamino)-6-oxo-5-((S)-pyrrolidine-2-carboxamido)hexyl)carbamate(55)

A solution of compound 54 (250 mg, 0.41 mmol) in HCl in MeOH (10 mL, 3M) was stirred at 25° C. for 2 h and then concentrated in vacuum to giveproduct 55 (207 mg, 100%) as a white foam. MS (ESI): [M+H⁺]=493.3.

Step 5: Synthesis of (9H-fluoren-9-yl)methylN-[(5S)-5-{[(2S)-1-[(2S,3E,5S)-2-benzyl-5-{[(tert-butoxy)carbonyl]amino}-7-methyloct-3-enoyl]pyrrolidin-2-yl]formamido}-5-[(pro-pan-2-yl)carbamoyl]pentyl]carbamate(56)

To a solution of compound 55 (207 mg, 0.41 mmol) and(2S,5S,E)-2-benzyl-5-((tert-butoxycarbonyl)amino)-7-methyloct-3-enoicacid (70, Structure A1 (X₃=benzyl), synthesized from Journal of theAmerican Chemical Society, 2005, 127, 12460-12461; 2, and OrganicLetter, 2011, 13, 2318-2321) (177 mg, 0.49 mmol) in CH₂Cl₂ (5 mL) at 0°C. was added T₃P (340 mg, 0.53 mmol) and DIEA (106 mg, 0.82 mmol). Thereaction mixture was allowed to warm to 25° C. and stirred for 16 h. Thereaction mixture was quenched with saturated aqueous NH₄Cl solution (10mL), and extracted by EtOAc (3×10 mL). The combined organic layer waswashed with aqueous HCl (2×10 mL, 1 M), saturated aqueous brine solution(3×10 mL), and dried over Na₂SO₄. The organic layer was concentrated invacuum and the residue was purified by silica gel column chromatography(petroleum ether/EtOAc=3:1 to 1:1) to give product 56 (308 mg, 89%) as awhite foam. MS (ESI): [M+H⁺]=836.5.

Step 6: Synthesis of tert-butyl((4S,7S,E)-8-((S)-2-(((S)-6-amino-1-(isopropylamino)-1-oxohexan-2-yl)carbamoyl)pyrrolidin-1-yl)-7-benzyl-2-methyl-8-oxooct-5-en-4-yl)carbamate(57)

To a solution of compound 56 (308 mg, 0.36 mmol) in CH₂Cl₂ (3 mL) wasadded DBU (164 mg, 1.08 mmol) at 25° C. and the mixture was stirred for30 min. Then the solvent was concentrated in vacuum to give product 57(225 mg, 100%) as a yellow oil. MS (ESI): [M+H⁺]=493.3.

Step 7: Synthesis of 1,4-dimethoxy-2,3,5-trimethylbenzene (59)

To a solution of compound 58 (10 g, 66 mmol) in acetone (100 mL) wasadded Me₂SO₄ (21.0 g, 165 mmol) and K₂CO₃ (36.0 g, 264 mmol). After thereaction mixture was stirred at 60° C. for 16 hours and thenconcentrated in vacuum. Saturated aqueous brine solution (200 mL) wasadded to the flask and the resulting mixture was extracted with EtOAc(3×50 mL). The combined organic layers were washed with water (2×50 mL)and dried over Na₂SO₄. The solvent was concentrated in vacuum and theresidue was subjected to silica gel column chromatography (petroleumether/EtOAc=20:1 to 10:1) to give product 59 (7.2 g, 61%) as a whitesolid.

Step 8: Synthesis of 2,5-dimethoxy-3,4,6-trimethylbenzaldehyde (60)

The compound 59 (7.2 g, 40 mmol) was dissolved in TFA (50 mL) and thenhexamine (6.2 g, 44 mmol) was added to the above solution. The reactionmixture was refluxed under dry conditions for 2 hours. The solvent ofTFA was evaporated under reduced pressure, and the residue was dissolvedin EtOAc (50 mL) and the organic solution was washed with water (3×50mL) and then dried over Na₂SO₄. The organic layer was concentrated invacuum and the residue was subjected to silica gel column chromatography(petroleum ether/EtOAc=20:1 to 10:1) to give product 60 (4.5 g, 54%) asa white solid.

Step 9: Synthesis of ethyl3-(2,5-dimethoxy-3,4,6-trimethylphenyl)acrylate (61)

To a solution of ethyl 2-(diethoxyphosphoryl) acetate (3.4 g, 15 mmol)in THF (20 mL) was added NaH (600 mg, 15 mmol) at 0° C., after thereaction mixture was stirred at 0° C. for 15 min., then a solution ofcompound 60 (2.1 g, 10 mmol) in THF (10 mL) was added. The reactionmixture was stirred for 1 h, and then quenched with water (40 mL) andextracted with EtOAc (50 mL). The organic layer was washed with water(2×50 mL), and dried over Na₂SO₄. The organic layer was concentrated invacuum and the residue was subjected to column chromatography on silicagel (petroleum ether/EtOAc=20:1 to 10:1) to give product 61 (2.2 g, 79%)as a white solid. MS (ESI): [M+H⁺]=278.9.

Step 10: Synthesis of ethyl3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propanoate (62)

The compound 61 (2.2 g, 7.9 mmol) was dissolved in methanol (20 mL),then Pd/C (50 mg, 10% w/w) was added to the above solution. The reactionmixture was stirred at room temperature in a hydrogen atmosphere for 2hours. The mixture was filtered and the filtrate was concentrated invacuum to give product 62 (2.2 g, 100%) as a yellow oil. ¹H NMR (400MHz, CDCl₃) δ 3.17-3.14 (dd, J=4.0 Hz, 2H), 3.68 (s, 3H), 3.65 (s, 3H),2.93-2.95 (m, 2H), 2.46-2.49 (m, 2H), 2.23 (s, 3H), 2.20 (s, 6H),2.25-2.28 (t, J=4.0, 8.0 Hz, 3H).

Step 11: Synthesis of 3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propan-1-ol(63)

The compound 62 (500 mg, 1.8 mmol) was dissolved in THF (10 mL)following by adding LiAlH₄ (80 mg, 2.1 mmol) into the resulting solutionat 0° C. The reaction mixture was stirred for 1 h at 0° C. and thensequentially quenched with water (0.81 mL), aqueous NaOH (0.81 mL, 10%)and water (0.81 mL). The mixture was diluted with EtOAc (20 mL) anddried over MgSO₄. The mixture was stirred for 10 min., filtered and thefiltrate was concentrated in vacuum to give product 63 (320 mg, 75%) asa yellow oil. MS (ESI): [M+H⁺]=238.9. ¹H NMR (400 MHz, CDCl₃) δ 3.68 (s,3H), 3.65 (s, 3H), 3.49 (s, 2H), 2.76-2.71 (m, 3H), 2.22 (s, 3H), 2.18(s, 6H), 1.76-1.74 (m, 2H).

Step 12: Synthesis of2-(3-hydroxypropyl)-3,5,6-trimethylcyclohexa-2,5-diene-1,4-dione (64)

A solution of compounds 63 (320 mg, 1.3 mmol) in THF (10 mL) was dilutedwith water (5 mL), and an excess solution of ceric ammonium nitrate(CAN) (1.4 g, 2.6 mmol) in 5 mL water was added at 0° C. The mixture wasstirred at room temperature for 2 h. THF was removed under a vacuum andthe crude mixture was extracted with three portions of EtOAc (20 mL).The organic layer was washed with saturated aqueous brine solution (2×20mL) until a water washing reached pH 7.0-7.4, then dried over anhydrousNa₂SO₄ and concentrated in vacuum. The crude products were purified bysilica gel column chromatography (petroleum ether/EtOAc=5:1 to 2:1) togive product 64 (210 mg, 78%) as a yellow solid. MS (ESI): [M+H⁺]=208.9.¹H NMR (400 MHz, CDCl3) δ 3.58-3.56 (m, 2H), 2.60-2.57 (m, 2H), 2.12 (s,1H), 2.04-2.01 (m, 9H), 1.70-1.67 (m, 2H).

Step 13: Synthesis of3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propylcarbonochloridate (65)

To a solution of bis(trichloromethyl) carbonate (324 mg, 1.1 mmol) intoluene (10 mL) was added pyridine (100 mg, 15 mmol) at 0° C. andstirred for 30 min. Then a solution of compound 64 (200 mg, 0.85 mmol)in toluene (2 mL) was added, then the reaction was stirred at 0° C. for30 min., diluted with water (10 mL) and extracted with EtOAc (10 mL).The organic layer was washed with water (2×20 mL) and dried over Na₂SO₄.The organic layer was concentrated under reduced pressure and theresidue was subjected to silica gel column chromatography (petroleumether/EtOAc=20:1 to 10:1) to give product 65 (140 mg, 61%) as a red oil.MS (ESI): [M+H⁺]=271.2.

Step 14: Synthesis of 3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propanoicacid (66)

A solution of the compound 62 (500 mg, 1.8 mmol) in THF/MeOH (4.0/1.0mL) was treated with LiOH.H₂O (152 mg, 3.6 mmol, in 0.5 mL water). Thereaction mixture was stirred at 25° C. for 2 h, then the solvents wereremoved in vacuum and the resulting mixture triturated with EtOAc (20mL) and aqueous HCl (1 M) until pH 3. The organic phase was separatedfrom water phase and the water phase was extracted with EtOAc (2×10 mL).The combined organic layers were washed with saturated aqueous brinesolution (2×10 mL), dried over Na₂SO₄, and concentrated in vacuum toafford product 66 (430 mg, 95%), which was used in the next step withoutpurification. MS (ESI): [M+H⁺]=252.9.

Step 15: Synthesis of3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl) propanoic acid (67)

A solution of compounds 66 (430 mg, 1.7 mmol) in THF (8 mL) was dilutedwith water (2 mL), and an excess solution of ceric ammonium nitrate(CAN, 1.9 g, 3.4 mmol) in 5 mL water was added at 0° C. The mixture wasstirred at room temperature for 2 h. THF was removed under a vacuum andthe crude mixture was extracted with three portions of EtOAc (20 mL).The combined organic layers were washed with saturated aqueous brinesolution (20 mL) until a water washing reached pH ˜7.0, then dried overanhydrous Na₂SO₄ and concentrated in vacuum. The crude products werepurified by a silica-gel column chromatography (petroleumether/EtOAc=5:1 to 2:1) to give product 67 (300 mg, 80%) as a red oil.MS (ESI): [M+H⁺]=223.3.

Step 16: Synthesis of tert-butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-6-(3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propanamido)-1-(isopropylamino)-1-oxohexan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate(I)

To a solution of compound 57 (150 mg, 0.24 mmol) and 67 (59 mg, 0.26mmol) in CH₂Cl₂ (5 mL) was added T₃P (198 mg, 0.31 mmol) and DIEA (40mg, 0.31 mmol) at 0° C. The reaction mixture was allowed to warm to 25°C. and stirred for 2 h. The reaction mixture was quenched with saturatedaqueous NH₄Cl solution, and extracted by EtOAc (3×10 mL). The combinedorganic layer was washed with aqueous (5%) NaHCO₃, saturated aqueousbrine solution (3×10 mL) and dried over Na₂SO₄. After concentrationunder reduced pressure, the residue was purified by prep-HPLC (VenusilXBP C18(5 μm, 30×250 mm), 0.1% HCl in eluant) to give product I (40 mg,20%) as a yellow solid. MS (ESI): [M+H⁺]=832.5. ¹H NMR (400 MHz, CDCl₃)δ 7.24-7.12 (m, 5H), 6.74-6.73 (m, 1H), 6.32-6.39 (m, 2H), 5.41-5.55 (m,2H), 5.06 (s, 1H), 4.39-4.41 (m, 2H), 4.06-4.08 (m, 2H), 3.19-3.39 (m,6H), 2.76-2.79 (m, 3H), 2.28-2.29 (m, 2H), 1.18-2.05 (m, 37H), 0.85-0.87(m, 6H).

Step 17: Synthesis of tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-5-({[3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)-1-[(propan-2-yl)carbamoyl]pentyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(II)

To a solution of compound 57 (320 mg, 0.51 mmol) and compound 65 (165mg, 0.61 mmol) in CH₂Cl₂ (5 mL) was added DIEA (79 mg, 0.61 mmol) at 0°C. The reaction mixture was allowed to warm to 25° C. and stirred for 2h. The reaction mixture was quenched with saturated aqueous NH₄Clsolution (20 mL), and extracted by EtOAc (3×10 mL). The combined organiclayer was washed with saturated aqueous brine solution (3×10 mL) anddried over Na₂SO₄. The residue after concentration under reducedpressure was purified by prep-HPLC (Venusil XBP C18(5 um, 30×250 mm),0.1% HCl in eluant) to give product II (70 mg, 16%) as a yellow solid.MS (ESI): [M+H⁺]=862.6. ¹H NMR (400 MHz, CDCl₃) δ 7.24-7.12 (m, 5H),6.8-6.70 (m, 1H), 6.25-6.26 (m, 1H), 5.39-5.57 (m, 2H), 5.03 (s, 1H),4.40-4.41 (m, 2H), 4.01-4.07 (m, 3H), 3.11-3.38 (m, 5H), 2.50-2.54 (m,2H), 1.17-2.00 (m, 43H), 0.84-0.87 (m, 6H).

Step 18: Synthesis of tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-5-[({[10-(4,5-dimethoxy-2-methyl-3,6-dioxocyclohexa-1,4-dien-1-yl)decyl]oxy}carbonyl)amino]-1-[(propan-2-yl)carbamoyl]pentyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(III)

To a solution of compound 57 (110 mg, 0.18 mmol) and compound 69 (77 mg,0.2 mmol, synthesized by methods analog for compound 65) in CH₂Cl₂ (5mL) was added DIEA (47 mg, 0.36 mmol) at 0° C. The reaction mixture wasallowed to warm to 25° C. and stirred for 2 h. The reaction mixture wasquenched with saturated aqueous NH₄Cl solution (20 mL), and extracted byEtOAc (3×10 mL). The combined organic layer was washed with saturatedaqueous brine (3×10 mL) solution and dried over Na₂SO₄. The residueafter concentration under reduced pressure and was purified by prep-HPLC(Venusil XBP C18(5 μm, 30×250 mm), 0.1% HCl in eluant) to give productIII (40 mg, 22%) as a yellow solid. MS (ESI): [M+H⁺]=992.7. ¹H NMR (400MHz, CDCl₃) δ 7.24-7.12 (m, 5H), 6.71-6.69 (m, 1H), 6.30-6.28 (m, 1H),5.58-5.57 (m, 1H), 5.44-5.39 (m, 1H), 5.07 (s, 1H), 4.41-4.40 (m, 2H),4.07-3.97 (m, 9H), 3.38-3.11 (m, 6H), 2.72-2.68 (m, 2H), 2.44-2.43 (m,2H), 2.02-1.17 (m, 50H), 0.86-0.84 (m, 6H).

Example 2: tert-Butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-6-(3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propanamido)-1-(isopropylamino)-1-oxohexan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate (IV) and Synthesis of tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-5-({[3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)-1-[(propan-2-yl)carbamoyl]pentyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(V)

Step 1: Synthesis of 1,4-dimethoxy-2,3-dimethylbenzene (72)

To a solution of compound 71 (5 g, 36.2 mmol) in acetone (100 mL) wasadded Me₂SO₄ (18.2 g, 144.8 mmol) and K₂CO₃ (25 g, 181 mmol). After thereaction mixture was stirred at 60° C. for 16 hours and then the solventwas concentrated in vacuum. Saturated aqueous brine solution (200 mL)was added to the flask and the resulting mixture was extracted withEtOAc (3×50 mL). The combined organic layers were washed with water(2×50 mL) and dried over Na₂SO₄. The solvent was evaporated underreduced pressure and the residue was subjected to silica gel columnchromatography (petroleum ether/EtOAc=20:1 to 10:1) to give product 72(5.5 g, 92%) as a white solid.

Step 2: Synthesis of 2,5-dimethoxy-3,4-dimethylbenzaldehyde (73)

The compound 72 (5 g, 30.1 mmol) was dissolved in TFA (50 mL) andhexamine (4.7 g, 33.1 mmol) was added to the resulting solution. Thereaction mixture was refluxed under dry conditions for 2 hours. The TFAwas evaporated under reduced pressure and the residue was dissolved inEtOAc (100 mL). and the resulting organic solution was washed with water(3×50 mL) and then dried over Na₂SO₄. The solvent organic phase wasevaporated concentrated in vacuum and the residue was subjected tosilica gel column chromatography (petroleum ether/EtOAc=20:1 to 10:1) togive product 73 (3.1 g, 53%) as a white solid.

Step 3: Synthesis of ethyl 3-(2,5-dimethoxy-3,4-dimethylphenyl)acrylate(74)

To a solution of ethyl 2-(diethoxyphosphoryl)acetate (3.1 g, 16 mmol) inTHF (20 mL) was added NaH (660 mg, 16 mmol) at 0° C., and the reactionmixture was stirred at 0° C. for 15 min., and then a solution of 73 (2.2g, 10.2 mmol) in THF (10 mL) was added. The reaction mixture was stirredfor 10 min, water (40 mL) was added and the result was extracted withEtOAc (50 mL). The organic layer was washed with water (2×50 ml) anddried over Na₂SO₄. The solvent in the organic layer was evaporated underreduced pressure and the residue was subjected to silica gel columnchromatography (petroleum ether/EtOAc=20:1 to 10:1) to give product 74(3.4 g, 81%) as a white solid.

Step 4: Synthesis of ethyl3-(2,5-dimethoxy-3,4-dimethylphenyl)propanoate (75)

The compound 74 (3.4 g, 7.9 mmol) was dissolved in methanol (20 mL) andthen Pd/C (50 mg, 10% w/w) was added to the above solution. The reactionmixture was stirred at room temperature under a hydrogen atmosphere for2 hours. The mixture was filtered and the filtrate was concentrated invacuum to give product 75 (3.4 g, 100%) as a yellow oil. MS (ESI):[M+H⁺]=266.9.

Step 5: Synthesis of 3-(2,5-dimethoxy-3,4-dimethylphenyl)propan-1-ol(76)

The compound 75 (500 mg, 1.9 mmol) was dissolved in THF (10 mL) and thenLiAlH₄ (80 mg, 2.1 mmol) was added to the resulting solution at 0° C.The reaction mixture was stirred for 1 h at 0° C. and then sequentiallyquenched with water (0.81 mL), aqueous NaOH (0.81 mL, 10%) and water(0.81 mL). The mixture was added diluted with EtOAc (10 mL) and driedover MgSO₄. The mixture was stirred for 10 min and filtered, and thefiltrate was concentrated in vacuum to give product 76 (350 mg, 82%) asa yellow oil.

Step 6: Synthesis of5-(3-hydroxypropyl)-2,3-dimethylcyclohexa-2,5-diene-1,4-dione (77)

A solution of compounds 76 (350 mg, 1.6 mmol) in THF (10 mL) was dilutedwith water (5 mL), and an excess solution of ceric ammonium nitrate(CAN, 1.8 g, 3.2 mmol) in 5 mL water was added at 0° C. The mixture wasstirred at room temperature for 2 h. The progress of the reaction wasmonitored by TLC. After completion, THF was removed under a vacuum andthe crude mixture was extracted with three portions of EtOAc (3×20 mL).The combined organic layers were washed with saturated aqueous brinesolution, then dried over anhydrous Na₂SO₄ and concentrated in vacuum.The crude products were purified by silica-gel column chromatography(petroleum ether/EtOAc=5:1 to 2:1) to give product 77 (210 mg, 68%) as ayellow solid. MS (ESI): [M+H⁺]=194.8.

Step 7: Synthesis of3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propylcarbonochloridate (78)

To a solution of bis(trichloromethyl) carbonate (210 mg, 1.1 mmol) intoluene (10 mL) was added pyridine (100 mg, 15 mmol) at 0° C. andstirred for 30 min. Then a solution of compound 7 (200 mg, 0.85 mmol) intoluene (2 mL) was added to the reaction at 0° C. The reaction mixturewas stirred at 0° C. for 30 min, diluted with water (40 mL) andextracted with EtOAc (50 mL). The organic layer was washed with water(2×50 mL) and dried over Na₂SO₄. The organic layer was concentrated invacuum and the residue was subjected to silica gel column chromatography(petroleum ether/EtOAc=20:1 to 10:1) to give product 78 (140 mg, 50%) asa red oil. MS (ESI): [M+H⁺]=256.8.

Step 8: Synthesis of 3-(2,5-dimethoxy-3,4-dimethylphenyl)propanoic acid(79)

A solution of the compound 75 (500 mg, 1.9 mmol) in THF/MeOH (4.0/1.0mL) was treated with LiOH.H₂O (152 mg, 3.8 mmol, in 0.5 mL water) at 0°C. Then the reaction mixture was stirred at 25° C. for 2 h, and thesolvents were concentrated in vacuum and the resulting mixture wastriturated with EtOAc (20 mL) and aqueous HCl (1 M) until pH 3. Theorganic phase was separated from water phase. The water phase wasextracted with EtOAc (2×10 mL), and the combined organic layers werewashed with saturated aqueous brine solution (2×10 mL), dried overNa₂SO₄, and concentrated in vacuum to afford product 79 (380 mg, 84%),which was carried on crude to use in the next step without purification.MS (ESI): [M+H⁺]=238.9.

Step 9: Synthesis of3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propanoic acid (80)

A solution of compounds 79 (380 mg, 1.6 mmol) in THF (8 mL) was dilutedwith water (2 mL), and an excess solution of ceric ammonium nitrate(CAN) (1.9 g, 3.4 mmol) in 5 mL water was added at 0° C. The mixture wasstirred at room temperature for 2 h. The progress of the reaction wasmonitored by TLC. After completion, THF was removed under vacuum and thecrude residue was extracted with three portions of EtOAc (3×20 mL). Thecombined organic layers were washed with saturated aqueous brinesolution (20 mL), then dried over anhydrous Na₂SO₄ and concentrated invacuum. The crude products were purified by a silica gel columnchromatography (petroleum ether/EtOAc=5:1 to 2:1) to give product 80(110 mg, 33%) as a red oil. MS (ESI): [M+H⁺]=208.8.

Step 10: Synthesis of tert-butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-6-(3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propanamido)-1-(isopropylamino)-1-oxohexan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate (IV)

To a solution of compound 57 (150 mg, 0.24 mmol) and compound 80 (54 mg,0.26 mmol) in CH₂Cl₂ (5 mL) was added T₃P (198 mg, 0.31 mmol) and DIEA(40 mg, 0.31 mmol) at 0° C. The reaction mixture was allowed to warm to25° C. and stirred for 2 h. The reaction mixture was quenched withsaturated aqueous NH₄Cl solution (20 mL), and extracted with EtOAc (3×10mL). The organic layer was washed with aqueous (5%) NaHCO₃ (20 mL),brine (3×10 mL) and dried over Na₂SO₄. The residue was evaporated underreduced pressure and purified by prep-HPLC (Venusil XBP C18(5 μm, 30×250mm), 0.1% HCl in eluant) to give product IV (42 mg, 21%) as a yellowsolid. MS (ESI): [M+H⁺]=818.6. ¹H NMR (400 MHz, CDCl₃) δ 7.24-7.00 (m,6H), 6.64 (s, 1H), 6.33-6.31 (m, 1H), 5.62-5.56 (m, 1H), 5.44-5.41 (m,1H), 4.80 (s, 1H), 4.42-4.40 (m, 2H), 4.08-4.05 (m, 2H), 3.41-3.07 (m,5H), 2.77-2.41 (m, 3H), 2.07-1.17 (m, 37H), 0.88-0.86 (m, 6H).

Step 11: Synthesis of tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-5-({[3-(4,5-dimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)-1-[(propan-2-yl)carbamoyl]pentyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(V)

To a solution of compound 67 (320 mg, 0.51 mmol) and compound 88 (156mg, 0.61 mmol) in CH₂Cl₂ (5 mL) was added DIEA (79 mg, 0.61 mmol) at 0°C. The reaction mixture was allowed to warm to 25° C. and stirred for 2h. The reaction mixture was quenched with saturated NH₄Cl solution, andextracted by EtOAc (3×10 mL). The organic layer was washed with brine(3×10 mL) and dried over Na₂SO₄. The residue was concentrated in vacuumand purified by pre-HPLC (Venusil XBP C18(5 μm, 30×250 mm), 0.1% HCl ineluant) to give product V (45 mg, 10%) as a yellow solid. MS (ESI):[M+H^(+])=848.5. ¹H NMR (400 MHz, CDCl₃) δ 7.24-7.13 (m, 5H), 6.77-6.48(m, 2H), 5.62-5.56 (m, 1H), 5.44-5.41 (m, 1H), 5.39-5.20 (m, 1H),4.41-4.33 (m, 2H), 4.08-4.05 (m, 3H), 3.73-3.11 (m, 7H), 2.79-2.47 (m,2H), 2.01-1.17 (m, 39H), 0.87-0.85 (m, 6H).

Example 3: tert-Butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)car-bamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate(VI)

Step 1: Synthesis of (S)-1-benzyl 2-tert-butyl5-oxopyrrolidine-1,2-dicarboxylate (92)

To a solution of compound 91 (1 g, 5.4 mmol) in THF (20 mL) was addedNaH (238 mg, 5.95 mmol, 60% in oil), then the mixture was stirred at 250for 30 min, subsequently CbzCl (1.02 g, 5.95 mmol) was added to theabove mixture and the stirring was continued for further 20 h. Thesolution was concentrated in vacuum, saturated aqueous NH₄Cl solution(100 mL) was added to the residue and extracted with EtOAc (2×100 mL).The combined organic phase was dried over MgSO₄, filtered andconcentrated in vacuum. The crude product was purified on silica gelcolumn (petroleum ether/EtOAc=3:1) to obtain the titled compound 92 (1g, 58%) as a colorless oil. MS (ESI): [M+H⁺]=319.9.

Step 2: Synthesis of (S)-tert-butyl2-(((benzyloxy)carbonyl)amino)-5-hydroxypentanoate (93)

To a solution of compound 92 (1 g, 3.13 mmol), KH₂PO₄ (3.2 g, 23.5 mmol)in MeOH (25 mL) and H₂O (5 mL) was added NaBH₄ (893 mg, 23.5 mmol). Themixture was stirred at 25° C. for 1 h, then organic solution wasconcentrated in vacuum. To the residue was added EtOAc (100 mL) andwashed with H₂O (3×50 mL). The organic phase was dried over MgSO₄,filtered and concentrated in vacuum to obtain the titled compound 93 (1g, 100%) as a colorless oil. MS (ESI): [M+H⁺]=324.0.

Step 3: Synthesis of (S)-tert-butyl5-(benzo[d]thiazol-2-ylthio)-2-(((benzyloxy)carbonyl)amino)pentanoate(94)

To a solution of compound 93 (1 g, 3.13 mmol), benzo[d]thiazole-2-thiol(620 mg, 3.7 mmol), Ph₃P (969 mg, 3.7 mmol) in THF (30 mL) at 0° C. wasadded DIAD (747 mg, 3.7 mmol). The mixture was stirred at 0° C. for 3 h,then organic solution was concentrated in vacuum. To the residue wasadded EtOAc (100 mL) and washed with H₂O (3×50 mL). The organic phasewas concentrated and purified on silica gel column (petroleumether/EtOAc=5:1) to obtain the titled compound 94 (1.33 g, 90%) as acolorless oil. MS (ESI): [M+H⁺]=473.1.

Step 4: Synthesis of (S)-tert-butyl5-(benzo[d]thiazol-2-ylsulfonyl)-2-(((benzyloxy)carbonyl)amino)pentanoate(95)

To a solution of compound 94 (1.33 g, 2.8 mmol) in CH₂Cl₂ (30 mL) wasadded m-CPBA (1.07 g, 6.2 mmol). The mixture was stirred at 25° C. for 1h, then organic solution was concentrated in vacuum. To the residue wasadded EtOAc (100 mL) and washed with 2N Na₂CO₃ in water (3×50 mL). Theorganic phase was concentrated and purified by silica gel columnchromatography (petroleum ether/EtOAc=5:1) to obtain the titled compound95 (930 mg, 66%) as a colorless oil. MS (ESI): [M+H^(+])=505.1.

Step 5: synthesis of (S,Z)-tert-butyl2-(((benzyloxy)carbonyl)amino)-6-(2,5-dimethoxy-3,4,6-trimethylphenyl)hex-5-enoate(96)

To a solution of compound 95 (930 mg, 1.85 mmol) in THF (25 mL) at −78°C. was added KHMDS (6.1 mL, 6.1 mmol, 1M in THF) under N₂ atmosphere.The mixture was stirred at −78° C. for 30 min, then2,5-dimethoxy-3,4,6-trimethylbenzaldehyde (384 mg, 1.85 mmol) in THF (5mL) was added and stirred at −78° C. for 3 h, then warmed to 0° C. andstirred for another 0.5 h. The mixture was quenched with H₂O (50 mL) andextracted with EtOAc (50 mL). The organic phase was washed with brine(3×50 mL), concentrated and purified by silica gel column chromatography(petroleum ether/EtOAc=5:1) to obtain the titled compound 96 (443 mg,48%) as an orange oil. MS (ESI): [M+H⁺]=498.2.

Step 6: Synthesis of(S,Z)-2-(((benzyloxy)carbonyl)amino)-6-(2,5-dimethoxy-3,4,6-trimethylphenyl)hex-5-enoicacid (97)

To a solution of compound 96 (443 mg, 0.89 mmol) in CH₂Cl₂ (25 mL) wasadded TFA (1 mL). The mixture was stirred at 25° C. for 18 h, thenconcentrated in vacuum to obtain the titled compound 97 (393 mg, 100%)as a yellow solid. MS (ESI): [M+H⁺]=442.0.

Step 7: Synthesis of (S,Z)-benzyl(6-(2,5-dimethoxy-3,4,6-trimethylphenyl)-1-(isopropylamino)-1-oxohex-5-en-2-yl)carbamate(98)

To a solution of compound 97 (393 mg, 0.89 mmol), propan-2-amine (158mg, 2.7 mmol), DIEA (344 mg, 2.7 mmol) in CH₂Cl₂ (20 mL) was added T₃P(736 mg, 1.2 mmol). The mixture was stirred at 25° C. for 12 h, then theorganic solution was concentrated in vacuum. To the residue was addedEtOAc (100 mL) and washed with H₂O (3×50 mL). The organic phase wascollected and concentrated in vacuum to obtain the titled compound 98(430 mg, 100%) as a yellow solid. MS (ESI): [M+H⁺]=483.1.

Step 8: Synthesis of(S)-2-amino-6-(2,5-dimethoxy-3,4,6-trimethylphenyl)-N-isopropylhexanamide(99)

To a solution of compound 98 (430 mg, 0.89 mmol) in MeOH (10 mL) wasadded Pd/C (50 mg, 10%). The mixture was stirred at 25° C. under H₂atmosphere for 12 h, filtered, and the solids were washed with MeOH (5mL). The organic filtrates were combined and concentrated in vacuum toobtain the titled compound 99 (311 mg, 100%) as a yellow solid. MS(ESI): [M+H⁺]=351.0.

Step 9: synthesis of (S)-tert-butyl(6-(2,5-dimethoxy-3,4,6-trimethylphenyl)-1-(isopropylamino)-1-oxohexan-2-yl)carbamate(100)

To a solution of compound 99 (311 mg, 0.89 mmol), Et₃N (180 mg, 1.78mmol) in CH₂Cl₂ (15 mL) was added Boc₂O (215 mg, 0.98 mmol). The mixturewas stirred at 25° C. for 3 h, then the organic solution wasconcentrated. To the residue was added EtOAc (100 mL) and washed withH₂O (3×50 mL). The organic phase was collected and concentrated toobtain the titled compound 100 (401 mg, 100%) as a yellow solid. MS(ESI): [M+H⁺]=451.2.

Step 10: Synthesis of (S)-tert-butyl(1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)carbamate(101)

To a solution of compound 100 (401 mg, 0.89 mmol) in CH₃CN (10 mL) andH₂O (10 mL) was added CAN (975 mg, 1.78 mmol). The mixture was stirredat 25° C. for 3 h, then organic solution was concentrated in vacuum. Tothe residue was added EtOAc (100 mL) and washed with H₂O (3×50 mL). Theorganic phase was concentrated and purified by silica gel columnchromatography (petroleum ether/EtOAc=3:1) to obtain the titled compound101 (104 mg, 28%) as a yellow solid. MS (ESI): [M+H⁺]=421.1.

Step 11: synthesis of(S)-2-amino-N-isopropyl-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexanamide(102)

To the compound 101 (104 mg, 0.25 mmol) EtOAc (5 mL) was added HCl inMeOH (5 mL, 3 M) and then the mixture was stirred at 25° C. for 1 h. Theorganic solution was concentrated in vacuum to obtain the titledcompound 102 (79 mg, 100%) as a yellow solid. MS (ESI): [M+H⁺]=321.0.

Step 12: Synthesis of (S)-tert-butyl2-(((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)carbamoyl)pyrrolidine-1-carboxylate(103)

To a solution of compound 102 (79 mg, 0.25 mmol),(S)-1-(tert-butoxycarbonyl) pyrrolidine-2-carboxylic acid (81 mg, 0.38mmol), DIEA (97 mg, 0.75 mmol) in CH₂Cl₂ (10 mL) was added T₃P (206 mg,0.33 mmol). The mixture was stirred at 25° C. for 12 h and then themixture was concentrated in vacuum. To the residue was added EtOAc (100mL) and washed with H₂O (3×50 mL). The organic phase was collected andconcentrated in vacuum to obtain the titled compound 103 (129 mg, 100%)as a yellow solid. MS (ESI): [M+H⁺]=510.2.

Step 13: Synthesis of(S)—N—((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)pyrrolidine-2-carboxamide(104)

To the compound 103 (129 mg, 0.25 mmol) was added HCl in MeOH (3 mL, 3M) and EtOAc (3 mL) and then the mixture was stirred at 25° C. for 1 h.The organic solution was concentrated in vacuum to obtain the titledcompound 104 (104 mg, 100%) as a yellow solid. MS (ESI): [M+H⁺]=418.1.

Step 14: Synthesis of tert-butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate(VI)

To a solution of compound 104 (104 mg, 0.25 mmol),(2S,5S,E)-2-benzyl-5-((tert-butoxycarbonyl)amino)-7-methyloct-3-enoicacid (70, 90 mg, 0.25 mmol), DIEA (97 mg, 0.75 mmol) in CH₂Cl₂ (10 mL)was added T₃P (206 mg, 0.33 mmol). The mixture was stirred at 25° C. for2 h and concentrated in vacuum. To the residue was added EtOAc (50 mL)and washed with H₂O (3×50 mL). The organic phase was concentrated andpurified by prep-HPLC (Durashell C18 (10 um, 30×250 mm), 0.5% NH₃.H₂O ineluant) to obtain the titled compound VI (52 mg, 27%) as a yellow solid.MS (ESI): [M+H⁺]=761.5. ¹H NMR (400 MHz, CDCl₃) δ 7.26-7.24 (m, 2H),7.14-7.13 (m, 2H), 6.64 (d, 1H), 6.37 (d, 1H), 5.61-5.57 (m, 1H),5.46-5.43 (m, 1H), 5.24 (d, 1H), 4.42 (s, 1H), 4.32 (s, 1H), 4.08-4.06(m, 2H), 3.56 (s, 1H), 3.38-3.37 (m, 1H), 3.23-3.22 (m, 1H), 3.16-3.12(m, 1H), 2.78-2.75 (m, 1H), 2.44-2.39 (m, 2H), 1.98-1.85 (m, 16H), 1.50(s, 1H), 1.41-1.24 (m, 12H), 1.21-1.18 (m, 8H), 0.86-0.83 (m, 6H).

Example 4: ethyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)carbamoyl)pyrrolidin1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate (VII)

Step 1: Synthesis of(S)-1-((2S,5S,E)-5-amino-2-benzyl-7-methyloct-3-enoyl)-N—((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)pyrrolidine-2-carboxamide(108)

To a 50-mL single-neck flask was added the compound VI (15 mg, 0.02mmol) and HCl in MeOH (5 mL, 3N), then the mixture was stirred at 25° C.for 1 h. The organic solution was concentrated in vacuum to obtain thetitled compound 108 (13 mg, 100%). MS (ESI): [M+H+]=661.3.

Step 2: Synthesis of ethyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-1-(isopropylamino)-1-oxo-6-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)hexan-2-yl)carbamoyl)pyrroli-din1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate (VII)

To a solution of 108 (13 mg, 0.02 mmol) and DIEA (5 mg, 0.04 mmol) inDCM (5 mL) was added ethyl chloroformate (2 mg, 0.02 mmol), then thereaction was stirred at 25° C. for 0.5 h. To the mixture was added DCM(50 mL) and washed with H₂O (3×50 mL). The organic phase wasconcentrated in vacuum and purified by prep-HPLC (Durashell C18(10 um,30×250 mm), 0.5% NH₃—H₂O in eluant) to obtain the titled compound VII (9mg, 60%) as a yellow solid. MS (ESI): [M+H⁺]=733.4. ¹H NMR (400 MHz,CDCl₃) δ 7.23-7.13 (m, 5H), 5.63-5.57 (m, 1H), 5.43-5.33 (m, 2H),4.44-4.33 (m, 1H), 4.14-4.04 (m, 3H), 3.56-3.12 (m, 4H), 2.79-2.74 (m,1H), 2.45-2.38 (m, 1H), 2.08-2.01 (m, 1H), 1.99 (s, 9H), 1.94-1.84 (m,2H), 1.52-1.15 (m, 24H), 0.87-0.84 (m, 6H).

Example 5: tert-butyl N-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-4-({[3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy]carbonyl}amino)-1-[(propan-2-yl)carbamoylbutyl]carbamoyl}-2-methylpropyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(VIII)

Step 1: Synthesis of tert-butylN-[(4S,5E,7S)-7-benzyl-8-[(2S)-2-{[(1S)-1-{[(1S)-4-({[3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy]carbonyl}amino)-1-[(propan-2-yl)carbamoyl]-butyl]carbamoyl}-2-methylpropyl]carbamoyl}pyrrolidin-1-yl]-2-methyl-8-oxooct-5-en-4-yl]carbamate(VIII)

To a solution of 56 (160 mg, 0.17 mmol) in DCM (5 mL) was added DBU (130mg, 0.86 mmol). The reaction was stirred at 25° C. for 15 min, then3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl carbonochloridate (110, 56mg, 0.19 mmol) was added and the mixture was stirred at 25° C. for 30min. To the mixture was added DCM (50 mL) and washed with H₂O (3×50 mL).The organic phase was concentrated in vacuum and purified by prep-HPLC(Durashell C18(10 μm, 30×250 mm), 0.5% NH₃.H₂O in eluant) to obtain thetitled compound VIII (20 mg, 12%) as a white solid. MS (ESI):[M+H^(+])=977.7.

¹H NMR (400 MHz, CDCl₃) δ 7.23-7.13 (m, 5H), 6.82 (d, 1H), 6.53 (d, 1H),5.63-5.34 (m, 2H), 4.90-4.69 (m, 1H), 4.42-4.03 (m, 6H), 3.62 (s, 6H),3.60-3.14 (m, 6H), 2.76-2.62 (m, 3H), 2.30-2.26 (m, 1H), 2.16 (s, 9H),2.04-0.84 (m, 43H).

Example 6: CyclopropylmethylN-[(4S,5E,7S)-7-benzyl-2-methyl-8-oxo-8-(2S)-2-{[(1S)-1-[(propan-2-yl)carbamoyl]-5-({[3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)pentyl]carbamoyl}pyrrolidin-1-yl]oct-5-en-4-yl]carbamate(IX)

Step 1: Synthesis of cyclopropylmethyl carbonochloridate (112)

To a solution of bis(trichloromethyl) carbonate (10.6 g, 36.1 mmol) intoluene (50 mL) was added pyridine (2.6 g, 33.4 mmol) at 0° C., and themixture was stirred for 30 min. Then a solution of 111 (2.0 g, 27.8mmol) in toluene (5 mL) was added. The reaction was stirred for 30 min,water (40 mL) was added and extracted with EA (50 mL). The organiclayers were washed with water (2×50 mL) and dried over Na₂SO₄. Thesolvent was concentrated in vacuum and the residue was subjected tocolumn chromatography on silica gel (petroleum ether/EtOAc=20:1 to 10:1)to give the titled compound 112 (2.9 g, 78%) as an oil.

Step 2: Synthesis of3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propyl((S)-5-((S)-1-((2S,5S,E)-5-amino-2-benzyl-7-methyloct-3-enyl)pyrrolidine-2-carboxamido)-6-(isopropylamino)-6-oxohexyl)carbamate(113)

A solution of compound IV (20 mg, 0.02 mmol) in HCl in MeOH (5 mL, 4 N)was stirred at 25° C. for 2 h and then the solvent was concentrated invacuum to give the titled product 113 (15 mg, 100%) as a white foam. MS(ESI): [M+H⁺]=762.4.

Step 3: Synthesis of cyclopropylmethyl N-[(4S,5E,7S)-7-benzyl-2-methyl-8-oxo-8-[(2S)-2-{[(1S)-1-[(propan-2-yl)carbamoyl]-5-({[3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)pentyl]carbamoyl}pyrrolidin-1-yl]oct-5-en-4-yl]carbamate(IX)

To a solution of compound 113 (15 mg, 0.02 mmol) and compound 112 (4 mg,0.24 mmol) in DCM (5 mL) was added DIEA (5 mg, 0.04 mmol) at 0° C. Thereaction mixture was allowed to warm to 25° C. and stirred for 2 h. Thereaction mixture was quenched with saturated NH₄Cl solution (10 mL), andextracted by EA (3×10 mL). The organic layer was washed with aqueousbrine (20 mL) and dried over Na₂SO₄. The residues were concentratedunder reduced pressure and purified by prep-HPLC (Durashell C18(10 μm,30×250 mm), 0.1% NH₃.H₂O in eluant) to give the product IX (9 mg, 53%)as a yellow solid.

MS (ESI): [M+H⁺]=860.6. ¹H NMR (400 MHz, CDCl₃) δ 7.23-7.13 (m, 5H),6.78-6.76 (m, 1H), 6.30-6.29 (m, 1H), 5.60-5.33 (m, 2H), 4.42-3.81 (s,4H), 3.58-3.13 (m, 4H), 2.72-2.68 (m, 1H), 2.55-2.53 (m, 1H), 2.01-1.83(m, 40H), 0.88-0.86 (m, 6H), 0.542-0.52 (m, 2H), 0.25-0.24 (m, 2H).

Example 7: tert-Butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-1-(isopropylamino)-1-oxo-3-(4-(3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy)phenyl)propan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate(X)

Step 1: Synthesis of(S)-2-((tert-butoxycarbonyl)amino)-3-(4-hydroxyphenyl) propanoic acid(122)

To a solution of compound 121 (2.0 g, 11.0 mmol) in dioxane/H₂O (20/10mL) was added Na₂CO₃ (3.5 g, 33.0 mmol) and Boc₂O (3.5 g, 16.5 mmol) at0° C. The reaction mixture was allowed to warm to 25° C. and stirred for16 h and then was removed under vacuum. Water vacuum. Water (20 mL) wasadded to the mixture, and extracted by EA (10 mL). The water layer wasadded HCl (4M in water) until pH=2-3 and extracted by EA (3×10 mL). Thecombined organic layer was washed with aqueous brine (20 mL), dried overNa₂SO₄ and concentrated in vacuum to give the titled product 122 (2.8 g,90%) as a yellow solid.

MS (ESI): [M+H⁺]=281.9.

Step 2: Synthesis of (S)-tert-butyl(3-(4-hydroxyphenyl)-1-(isopropylamino)-1-oxopropan-2-yl) carbamate(123)

To the solution of compound 122 (2.8 g, 9.9 mmol) and propan-2-amine(0.88 g, 14.9 mmol) in DCM (20 mL) at 0° C. was added DIEA (2.6 g, 19.8mmol), T₃P (50% in EA, 9.4 g, 14.9 mmol) was added slowly, and thereaction mixture was allowed to warm to 25° C. and stirred for 18 h. Thereaction mixture was washed with 5% aqueous Na₂CO₃ (10 mL) and water (20mL), and the organic layer was dried over MgSO₄ and concentrated invacuum. The residual semisolids were dried under vacuum to obtain asolid product 123 (2.8 g, 88%). MS (ESI): [M+H⁺]=322.9.

Step 3: Synthesis of 3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl4-methylbenzenesulfonate (129)

To the solution of compound 110 (3.0 g, 12.6 mmol) in 10 mL DMF wasadded tosyl chloride (2.87 g, 15.1 mmol), and the mixture was stirred at0° C. for 10 min. Then, DIEA (1.9 g, 15.1 mmol) was added slowly to themixture, the reaction was stirred at 25° C. for 5 h, TLC was used tomonitor the reaction progress. The reaction was quenched by water (10mL), extracted by EA (3×20 mL). The combined organic layer was washed by5% aqueous NaHCO₃ (20 mL), saturated aqueous brine (3×20 mL), and driedover Na₂SO₄. The solvent was concentrated in vacuum to give an oilproduct 129 (3.0 g, yield 60%, purity 80%)

Step 4: Synthesis of (S)-tert-butyl(3-(4-(3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy)phenyl)-1-(isopropylamino)-1-oxopropan-2-yl)carbamate (124)

To a solution of compound 123 (0.5 g, 1.56 mmol) in DMSO (10 mL) wasadded K₂CO₃ (650 mg, 4.68 mmol) and3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl 4-methylbenzenesulfonate(129, 733 mg, 1.9 mmol) at 100° C. The reaction mixture was stirred for16 h, and then water was added the mixture and extracted by EA (2×10mL). The combine layer was washed with aqueous brine (20 mL), dried overNa₂SO₄ and concentrated in vacuum. The residue was subjected to columnchromatography on silica gel (petroleum ether/EtOAc=10:1 to 2:1) to givethe titled product 124 (350 mg, 41%) as an oil.

MS (ESI): [M+H⁺]=543.2.

Step 5: Synthesis of(S)-2-amino-3-(4-(3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy)phenyl)-N-isopropylpropanamide (125)

A solution of compound 124 (350 mg, 0.64 mmol) in HCl in MeOH (10 mL, 4M) was stirred at 25° C. for 2 h and then the solvent was concentratedin vacuum to give the titled product 125 (283 mg, 100%) as an oil. MS(ESI): [M+H⁺]=443.2.

Step 6: Synthesis of (S)-tert-butyl2-(((S)-3-(4-(3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy)phenyl)-1-(isopropylamino)-1-oxopropan-2-yl)carbamoyl)pyrrolidine-1-carboxylate (126)

To the solution of compound 125 (283 mg, 0.64 mmol) and(S)-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylic acid (70) (165 mg,0.77 mmol) in DCM (10 mL) at 0° C. was added DIEA (248 mg, 1.92 mmol),and T₃P (50% in EA, 9.4 g, 14.9 mmol) with dropwise, and the reactionmixture was allowed to warm to 25° C. and stirred for 16 h. The reactionmixture was washed with 5% aqueous Na₂CO₃ (10 mL) and water (40 mL), andthe organic layer was dried over MgSO₄ and concentrated in vacuum toobtain a solid product 126 (290 mg, 71%). MS (ESI): [M+H⁺]=640.3.

Step 7: Synthesis of (S)-tert-butyl2-(((S)-1-(isopropylamino)-1-oxo-3-(4-(3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy)phenyl)propan-2-yl)carbamoyl) pyrrolidine-1-carboxylate (127)

A solution of compound 126 (290 mg, 0.45 mmol) in THF (8 mL) was dilutedwith water (2 mL), and an excess solution of ceric ammonium nitrate(CAN) (543 mg, 0.99 mmol) in 5 mL water was added at 0° C. The mixturewas stirred at room temperature for 2 h. The progress of the reactionwas monitored by TLC. After completion, THF was removed under a vacuumand the crude mixture was extracted with three portions of EA (3×20 mL).The combined organic layer was washed with aqueous brine solution (20mL), then dried over anhydrous Na₂SO₄ and concentrated in vacuum. Thecrude products were purified by a silica-gel column chromatography(petroleum ether/EtOAc=5:1 to 2:1) to give the titled product 127 (160mg, 58%) as a yellow oil. MS (ESI): [M+H⁺]=610.2.

Step 8: Synthesis of(S)—N—((S)-1-(isopropylamino)-1-oxo-3-(4-(3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy)phenyl)propan-2-yl)pyrrolidine-2-carboxamide(128)

A solution of compound 127 (160 mg, 0.26 mmol) in HCl in MeOH (10 mL, 4M) was stirred at 25° C. for 2 h and then concentrated to give thetitled product 128 (132 mg, 100%) as an oil. MS (ESI): [M+H⁺]=510.1.

Step 9: Synthesis of tert-butyl((4S,7S,E)-7-benzyl-8-((S)-2-(((S)-1-(isopropylamino)-1-oxo-3-(4-(3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy)phenyl)propan-2-yl)carbamoyl)pyrrolidin-1-yl)-2-methyl-8-oxooct-5-en-4-yl)carbamate(X)

To the solution of compound 128 (132 mg, 0.26 mmol) and(2S,5S,E)-2-benzyl-5-((tert-butoxycarbonyl)amino)-7-methyloct-3-enoicacid (70, 113 mg, 0.31 mmol) in DCM (10 mL) at 0° C. was added DIEA (74mg, 0.57 mmol), and T₃P (50% in EA, 248 mg, 0.39 mmol), and the reactionmixture was allowed to warm to 25° C. and stirred for 16 h. The reactionmixture was washed with 5% Na₂CO₃ (10 mL) and water (20 mL), and theorganic layer was dried over MgSO₄ and concentrated in vacuum. Theresidues were purified by pre-HPLC (Durashell C18(10 m, 30×250 mm), 0.1%NH₃.H₂O in eluant) to obtain a yellow solid product X (42 mg, 19%). MS(ESI): [M+H^(+])=853.4. ¹H NMR (400 MHz, CDCl₃) δ 7.24-7.06 (m, 7H),6.76-6.62 (m, 2H), 5.669-5.31 (m, 3H), 4.43-4.39 (m, 2H), 4.15-3.88 (s,3H), 3.45-3.34 (m, 2H), 3.14-3.09 (m, 2H), 2.95-2.90 (m, 2H), 2.72-2.63(m, 2H), 2.00-0.87 (m, 43H).

Example 8: tert-butylN-[(4S,5E,7S)-7-benzyl-2-methyl-8-[(2S)-2-{[(1S)-2-methyl-1-{[(1S)-1-[(propan-2-yl)carbamoyl]-4-({[3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)butyl]carbamoyl}propyl]carbamoyl}pyrrolidin-1-yl]-8-oxooct-5-en-4-yl]carbamate(XI)

Step 1: Synthesis of (S)-tert-butyl(3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl)(5-(isopropylamino)-5-oxopentane-1,4-diyl)dicarbamate (133)

To a solution of 52 (500 mg, 1.01 mmol) in DCM (10 mL) was added DBU(768 mg, 5.05 mmol) at 0° C., the reaction mixture was stirred for 30min and allowed to warm to 25° C. and then compound 110 (364 mg, 1.21mmol) and DIEA (291 mg, 1.52 mmol) were added. After 30 min later, water(20 mL) was added to the mixture, and extracted by DCM (2×10 mL). Thecombined organic layer was washed with aqueous brine (20 mL), dried overNa₂SO₄ and concentrated in vacuum. The crude products were purified by asilica-gel column chromatography (petroleum ether/EtOAc=5:1 to 2:1) togive the titled product 133 (420 mg, 77%) as a yellow solid. MS (ESI):[M+H⁺]=538.2.

Step 2: Synthesis of (S)-3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl(4-amino-5-(isopropylamino)-5-oxopentyl)carbamate (134)

A solution of compound 133 (420 mg, 0.78 mmol) in HCl in MeOH (10 mL, 4M) was stirred at 25° C. for 2 h and then the solvent was concentratedin vacuum to give the titled product 134 (341 mg, 100%) as an oil. MS(ESI): [M+H⁺]=438.2.

Step 3: Synthesis of (S)-3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl(4-amino-5-(isopropylamino)-5-oxopentyl)carbamate (135)

To the solution of compound 134 (420 mg, 0.78 mmol) and(S)-2-((tert-butoxycarbonyl)amino)-3-methylbutanoic acid (203 mg, 0.93mmol) in DCM (10 mL) at 0° C. was added DIEA (221 mg, 1.72 mmol), andT₃P (50% in EA, 744 mg, 1.17 mmol), and the reaction mixture was allowedto warm to 25° C. and stirred for 16 h. The reaction mixture was washedwith 5% aqueous Na₂CO₃ (10 mL) and water (20 mL), and the organic layerwas dried over MgSO₄ and concentrated in vacuum to obtain a solidproduct 135 (420 g, 85%). MS (ESI): [M+H⁺]=637.2.

Step 4: Synthesis of 3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propyl((S)-4-((S)-2-amino-3-methylbutanamido)-5-(isopropylamino)-5-oxopentyl)carbamate(136)

A solution of 135 (420 mg, 0.66 mmol) in HCl in MeOH (10 mL, 4 M) wasstirred at 25° C. for 2 h and then concentrated in vacuum to give thetitled compound 136 (354 mg, 100%) as an oil. MS (ESI): [M+H⁺]=537.3.

Step 5: Synthesis of (S)-tert-butyl2-(((S)-1-(((S)-5-(((3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy)carbonyl)amino)-1-(isopropylamino)-1-oxopentan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)carbamoyl)pyrrolidine-1-carboxylate(137)

To the solution of compound 136 (354 mg, 0.66 mmol) and(S)-2-((tert-butoxycarbonyl)amino)-3-methylbutanoic acid (212 mg, 0.99mmol) in DCM (10 mL) at 0° C. was added DIEA (187 mg, 1.45 mmol), andT₃P (50% in EA, 630 mg, 0.99 mmol), and the reaction mixture was allowedto warm to 25° C. and stirred for 16 h. The reaction mixture was washedwith 5% aqueous Na₂CO₃ (10 mL) and water (20 mL), and the organic layerwas dried over MgSO₄ and concentrated in vacuum to obtain a solidproduct 137 (350 mg, 72%). MS (ESI): [M+H⁺]=734.3.

Step 6: Synthesis of (2S)-tert-butyl2-(((2S)-1-(((2S)-1-(isopropylamino)-1-oxo-5-(((3-(2,4,5-trimethyl-3,6-dioxocyclohex-1-en-1-yl)propoxy)carbonyl)amino)pentan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)carbamoyl)pyrrolidine-1-carboxylate(138)

A solution of compound 138 (350 mg, 0.48 mmol) in THF (8 mL) was dilutedwith water (2 mL), and an excess solution of ceric ammonium nitrate(CAN) (580 mg, 1.05 mmol) in 5 mL water was added at 0° C. The mixturewas stirred at room temperature for 2 h. The progress of the reactionwas monitored by TLC. After completion, THF solvent was removed under avacuum and the crude mixture was extracted with three portions of EA(3×20 mL). The organic extracts were washed with aqueous brine (2×20mL), then dried over anhydrous Na₂SO₄ and concentrated in vacuum. Thecrude products were purified by a silica-gel column chromatography(petroleum ether/EtOAc=5:1 to 2:1) to give the titled product 138 (190mg, 56%) as a yellow oil. MS (ESI): [M+H⁺]=704.4. ¹H NMR (400 MHz,CDCl₃) δ 7.13-6.56 (m, 3H), 5.03 (s, 1H), 4.44-3.99 (m, 6H), 3.75-3.44(m, 5H), 2.54-0.88 (m, 44H).

Step 7: Synthesis of3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propyl((S)-5-(isopropylamino)-4-((S)-3-methyl-2-((S)-pyrrolidine-2-carboxamido)butanamido)-5-oxopentyl)carbamate (139)

A solution of compound 138 (190 mg, 0.27 mmol) in HCl in MeOH (10 mL, 4M) was stirred at 25° C. for 2 h and then concentrated in vacuum to givethe titled product 138 (162 mg, 100%) as an oil.

MS (ESI): [M+H⁺]=604.3.

Step 8: Synthesis of tert-butylN-[(4S,5E,7S)-7-benzyl-2-methyl-8-[(2S)-2-{[(1S)-2-methyl-1-{[(1S)-1-[(propan-2-yl)carbamoyl]-4-({[3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy]carbonyl}amino)butyl]carbamoyl}propyl]carbamoyl}pyrrolidin-1-yl]-8-oxooct-5-en-4-yl]carbamate(XI)

To the solution of compound 139 (162 mg, 0.27 mmol) and(2S,5S,E)-2-benzyl-5-((tert-butoxycarbonyl)amino)-7-methyloct-3-enoicacid (70, 113 mg, 0.31 mmol) in DCM (10 mL) at 0° C. was added DIEA (74mg, 0.57 mmol), T₃P (50% in EtOAc, 248 mg, 0.39 mmol) slowly, and thereaction mixture was allowed to warm to 25° C. and stirred for 16 h. Thereaction mixture was washed with 5% aqueous Na₂CO₃ (10 mL) and water (20mL), and the organic layer was dried over MgSO₄ and concentrated invacuum. The residues were purified by prep-HPLC (Durashell C18(10 μm,30×250 mm), 0.1% NH₃.H₂O in eluant) to obtain a yellow solid product XI(45 mg, 18%). MS (ESI): [M+H⁺]=947.6.

¹H NMR (400 MHz, CDCl₃) δ=7.24-7.13 (m, 5H), 6.79-6.33 (m, 2H),5.63-5.27 (m, 3H), 4.79-4.03 (m, 6H), 3.57-2.50 (m, 7H), 2.00-0.85 (m,55H).

Example 9: 3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propylN-[(4S)-4-{[(2S)-1-[(2S,3E,5S)-2-benzyl-5-{[(tert-butoxy)carbonyl]amino}-7-methyloct-3-enoyl]pyrrolidin-2-yl]formamido}-4-(cyclopropylcarbamoyl)butyl]carbamate(XII)

Step 1: Synthesis of (S)-(9H-fluoren-9-yl)methyl tert-butyl(5-(cyclopropylamino)-5-oxopentane-1,4-diyl)dicarbamate (142)

To the solution of compound 141 (0.5 g, 1.1 mmol) and cyclopropylamine(94 g, 1.7 mmol) in DCM (10 mL) at 0° C. was added DIEA (220 mg, 1.7mmol), T₃P (50% in EA, 1.1 g, 1.7 mmol), and the reaction mixture wasallowed to warm to 25° C. and stirred for 16 h. The reaction mixture waswashed with 5% aqueous Na₂CO₃ and water, and the organic layer was driedover MgSO₄ and concentrated in vacuum to obtain a solid product 142 (480mg, 8968%). MS (ESI): [M+H⁺]=494.2.

Step 2: Synthesis of (S)-(9H-fluoren-9-yl)methyl(4-amino-5-(cyclopropylamino)-5-oxopentyl)carbamate (143)

A solution of compound 142 (480 mg, 0.98 mmol) in HCl in MeOH (10 mL, 4M) was stirred at 25° C. for 2 h and then concentrated in vacuum to givethe product 143 (385 mg, 100%) as an oil. MS (ESI): [M+H⁺]=394.0.

Step 3: Synthesis of (S)-tert-butyl2-(((S)-5-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-1-(cyclopropylamino)-1-oxopentan-2-carbamoyl)pyrrolidine-1-carboxylate(144)

To the solution of compound 143 (385 mg, 0.98 mmol) and(S)-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylic acid (316 mg, 1.47mmol) in DCM (10 mL) at 0° C. was added DIEA (278 mg, 2.2 mmol), T₃P(50% in EA, 934 mg, 1.47 mmol), and the reaction mixture was allowed towarm to 25° C. and stirred for 16 h. The reaction mixture was washedwith 5% aqueous Na₂CO₃ (20 mL), and the organic layer was dried overMgSO₄ and concentrated in vacuum to obtain a solid product 144 (390 mg,68%). MS (ESI): [M+H⁺]=591.2.

Step 4: Synthesis of (S)-tert-butyl2-(((S)-1-(cyclopropylamino)-5-(((3-(2,5-dimethoxy-3,4,6-trimethylphenyl)propoxy)carbonyl)amino)-1-oxopentan-2-yl)carbamoyl)pyrrolidine-1-carboxylate (146)

To a solution of compound 144 (390 mg, 0.67 mmol) in DCM (10 mL) wasadded DBU (510 mg, 3.35 mmol) at 0° C. The reaction mixture was allowedto warm to 25° C. and stirred for 30 min. and then added compound 110(240 mg, 0.8 mmol) and DIEA (110 mg, 0.8 mmol). Water was added themixture, and the mixture was extracted by DCM (2×10 mL). The combinedlayer was washed with aqueous brine (3×10 mL), dried over Na₂SO₄ andconcentrated in vacuum. The residue was purified via column (silica gel,PE/EA=3:1 to 1:1) to give the product 146 (340 mg, 75%) as a yellowsolid. MS (ESI): [M+H⁺]=633.4.

Step 5: Synthesis of (S)-tert-butyl2-(((S)-1-(cyclopropylamino)-1-oxo-5-(((3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propoxy)carbonyl)amino)pentan-2-yl) carbamoyl)pyrrolidine-1-carboxylate (147)

A solution of compound 146 (340 mg, 0.5 mmol) in THF (8 mL) was dilutedwith water (2 mL), and an excess solution of ceric ammonium nitrate(CAN) (602 mg, 1.1 mmol) in 5 mL water was added at 0° C. The mixturewas stirred at room temperature for 2 h. The progress of the reactionwas monitored by TLC. After completion, THF was removed under a vacuumand the crude mixture was extracted with three portions of EA (3×20 mL).The organic extracts were washed with aqueous brine (3×20 mL), thendried over anhydrous Na₂SO₄ and concentrated in vacuum. The crudeproducts were purified by a silica-gel column chromatography on silicagel (PE/EA=3:1 to 1:1) to give the product 147 (180 mg, 44%) as a yellowoil. MS (ESI): [M+H⁺]=603.2. ¹H NMR (400 MHz, CDCl₃) δ 7.26-6.77 (m,2H), 4.93 (s, 1H), 4.44-4.10 (m, 4H), 3.66-3.63 (m, 6H), 3.49-3.3.45 (m,4H), 2.68-2.64 (m, 3H), 2.20-1.25 (m, 28H), 0.72-0.53 (m, 4H).

Step 6: Synthesis of3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propyl((S)-5-(cyclopropylamino)-5-oxo-4-((S)-pyrrolidine-2-carboxamido)pentyl)carbamate (148)

A solution of compound 147 (180 mg, 0.22 mmol) in HCl in MeOH (10 mL, 4M) was stirred at 25° C. for 2 h and then the solvent was concentratedin vacuum to give the product 148 (110 mg, 100%) as an oil. MS (ESI):[M+H⁺]=503.2.

Step 7: Synthesis of3-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)propylN-[(4S)-4-{[(2S)-1-[(2S,3E,5S)-2-benzyl-5-{[(tert-butoxy)carbonyl]amino}-7-methyloct-3-enoyl]pyrrolidin-2-yl]formamido}-4-(cyclopropylcarbamoyl)butyl]carbamate(XII)

To the solution of compound 148 (110 mg, 0.22 mmol) and(2S,5S,E)-2-benzyl-5-((tert-butoxycarbonyl)amino)-7-methyloct-3-enoicacid (70, 95 mg, 0.26 mmol) in DCM (10 mL) at 0° C. was added DIEA (62mg, 0.48 mmol), T₃P (50% in EA, 210 mg, 0.33 mmol), and the reactionmixture was allowed to warm to 25° C. and stirred for 16 h. The reactionmixture was washed with 5% aqueous Na₂CO₃ (20 mL) and water (20 mL), andthe organic layer was dried over MgSO₄ and concentrated in vacuum. Theresidues were purified by prep-HPLC (Durashell C18(10 μm, 30×250 mm),0.1% NH₃.H₂O in eluant) to obtain a yellow solid product XII (15 mg,8%). MS (ESI): [M+H^(+])=846.5. ¹H NMR (400 MHz, CDCl₃) δ 7.25-7.09 (m,8H), 5.61-5.27 (m, 3H), 4.33 (s, 2H), 4.02 (s, 2H), 3.60-2.75 (m, 12H),1.98-0.58 (m, 39H).

Example 10 Primary Screening by Ferroptosis Assay

Cell Lines and Media:

HT-1080 (fibrosarcoma) cells were obtained from American Type CultureCollection. Cells were grown in EMEM media, 10% Heat-Inactivated FBS,and penicillin-streptomycin mix (Invitrogen). Cells were maintained at37° C. and 5% CO₂ in a tissue culture incubator.

Cell Viability Assay.

Seed 10,000 cell/well of HT-1080 cells with 195 μL growth media in blackand clear bottom 96-well plates (Cat #Corning3904) and allow cells toadhere overnight. The next day, dilute test compound by 2-fold dilutioninto 12 points with medium containing 400 μM Erastin. Transfer 5 μL ofcompounds solution into growth medium in triplicated wells. 30 hourslater, add Cell Titer-Glo® Luminescent cell viability assay reagent (Cat#, Promega G8081) to measure HT-1080 cell viability according to themanufacture protocol. Briefly, aspirate 100 μL medium, and add 50 μLCellTiter-Glo® Luminescent reagent to each well and incubated for 30minutes at room temperature to stabilize the Luminescent signal. Sealthe plates and centrifuged for 1 minute at 1,000 rpm to remove bubbles.Shake the plates for 1 minute on an orbital shaker. Read the plate todetect Luminescent signal with EnSpire Multimode Plate Reader(PerkinElmer). The remaining activity % is used to evaluate Erastininduced ferroptosis in HT-1080 cells and expressed as the followingformula:% RemainingActivity=100×[(Sample−Background_(avg))/(Vehicle−Background_(avg))]

Sample: Readout from the test compound

Vehicle: Readout from the vehicle sample

Background: Readout from the Erastin only treatment

Dose response curve is graphed by using the non-linear regressionanalysis (formula equation 201) in XLFit (Excel add-in software) for theaverage % remaining activity from triplicates, and the EC50 values isthen calculated. In this anti-ferroptosis assay, ferrostatin-1, andXJB-5-131 are included as reference. The acceptance criteria were setbased on historical result, mean±2.58*SD in logarithmic scale, meanwhileZ′>0.5.

TABLE 1 Summary of Example Compounds Inhibition for Ferroptosis inHT-1080 Cell. Example ID EC50/nM I 118.98 II 32.96 III 34.57 IV 24.38 V196.06 VI 39.06 VII 80.55 VIII >6000 IX 49.29 X 56.86 XI 47.01 XII148.72

Example 11 Apoptosis Assay

Cell Lines and Media.

3T3-L1 cells were obtained from American Type Culture Collection. Cellswere grown in DMEM completed media, 10% FBS, and penicillin-streptomycinmix (Invitrogen). Cells were maintained at 37° C. and 5% CO₂ in a tissueculture incubator.

Apoptosis Assay.

Promega's Caspase-Glo® 3/7 assay uses a luminogenic substrate containingthe DEVD sequence, which has been shown to be selective for caspase-3and -7. We used this assay to screen our compounds for apoptosisinhibition. Briefly, 40 μL of 3000 3T3-L1 cells were seeded per well in384 well plates, Cells were allowed to adhere overnight. In the nextday, prepare the Actinomycin D as the apoptosis inducing agent into 100μM DMSO stock. Prepare the test compounds into 10 mM DMSO stock. Serialdilute the compound into 10 points by 3-fold dilution with DMSO.Pre-treat the 3T3-L1 cells with test compound by transfer 40 nL of stockof serial concentration in triplicate wells using acoustic fluidtransfer, incubate for 2 hours. Then transfer 40 nL of 100 μM ofActinomycin D (final concentration is 100 nM) into designated wellsusing acoustic fluid transfer. Incubate the assay plates at 37° C., 5%CO₂, 95% humidity incubator for 48 hours. For caspase assay, add 20μL/well of Caspase-Glo® 3/7 reagent (Promega) into test wells. Incubatefor 30 minutes at room temperature to stabilize the luminescence signal.Read the plate with EnSpire Multimode Plate Reader (PerkinElmer).Calculate the EC50 value using formula equation 201: y=(A+((B−A)(+((x/C)∧D)))) from the XLFit (Excel add-in software), where

A: Average mean of vehicle samples

B: Average mean of cells treated with 100 nM AcD

C: EC50

D: HillSlope

Z′ factor was used to describe the screening assay performance. The Z′factor value was >0.5 in all the test plates which indicated the assaywas qualified and the IC50 value was reliable for all tested compounds.

TABLE 2 Summary of Example Compounds Inhibition for Apoptosis in 3T3-L1Cell induced by Actinomycin D. Example Compounds EC50/μM I 1.152 II0.808 II 1.566 IV 0.702 V 2.745 VI 7.317

Example 12 Lipid ROS Assay to Evaluate Compound

DCFDA—Cellular Reactive Oxygen Species Detection Assay Kit from Abcam(ab113851) was used to detect cellular (lipid) ROS in HT-1080 cellsinduced by Erastin.

DCFDA—Cellular ROS Detection Assay Kit (ab113851) uses the cell permeantreagent 2′,7′-dichlorofluorescin diacetate (DCFDA), a fluorogenic dyethat measures hydroxyl, peroxyl and other reactive oxygen species (ROS)activity within the cell. After diffusion into the cell, DCFDA isdeacetylated by cellular esterases to a non-fluorescent compound, whichis later oxidized by ROS into 2′, 7′-dichlorofluorescein (DCF). DCF is ahighly fluorescent compound which can be detected by fluorescencespectroscopy with maximum excitation and emission spectra of 495 nm and529 nm respectively

Lipid ROS Assay.

25000 HT-1080 cells were seeded into black and clear bottom 96-wellplates, let the HT-1080 cells adhere overnight. Next day, treat thecells with cytotoxic agent (Erastin, 50 μM) and incubate with testcompounds (10 points, 3-fold series dilution) for 24 hours. Wash cellsin 1×PBS and stain cells with DCFDA reagent for 30-45 minutes at 37° C.incubator according to the manufacture protocol (Ab113851). Measurefluorescence (Ex/Em=485/535 nM) in the assay plates using EnSpireMultimode Plate Reader (PerkinElmer). Determine the ROS change as apercentage of control after background subtraction. Dose response curvewas graphed by using the non-linear regression analysis in XLFitsoftware for the average % ROS change from duplicates, and the EC50values were calculated. In addition, lipid ROS can also be measured byflow cytometry using the FL1 channel (green fluorescence), or byfluorescence microscopy. The fluorescence can be detected by usingexcitation and emission wavelengths that are appropriate for greenfluorescence.

Example compounds were used to test the ability of inhibition on thelipid ROS assay, most of examples have the ability inhibition on lipidROS with IC50 less than 1 mM.

Example 13a Ischemia Reperfusion (IR) Induced Acute Kidney Injury (AKI)Animal Model

Mice were anesthetized with a 5% chloral hydrate (400 mg/kg 5% chloralhydrate). Bilateral renal ischemia was induced by the application ofnon-traumatic micro-vascular clamps around both left and right renalpedicles. Ischemia was confirmed by blanching of the kidneys. After30-minute ischemia, the clamps were removed and reperfusion wasconfirmed visually. Sham-operated animals were not subjected toischemia. During the ischemic interval, the animals were kept hydratedwith normal saline instilled intraperitoneally and were kept on warmheating pads to maintain body temperature.

Animals were randomly assigned to the following groups: Sham operated,IR with saline, or IR with test article (5.0 mg/kg, 15 mg/kg). Treatmentwas administered subcutaneously 2 h before onset of ischemia, at theonset of reperfusion, and at 2 hours after reperfusion. Serum and urinesamples were collected at 24 hours and stored at −20° C. until analysis.Kidneys were harvested at different times after onset of reperfusion 24hours for assessment of oxidative markers, and histopathology by lightand electron microscopy.

The effect of example compounds not only decrease the creatinine and BUNto normal function level, but also shown protection on the kidneyhistological damage in renal IR.

Example 13b Folic Acid-Induced Acute Kidney Injury (AKI) Animal Model

Mice were divided into four groups, sham control, folic acid treatmentgroup that contains the following sub groups: article 1 treatment group,article 2 treatment group, and DMSO (vehicle control) group. Mice weredosed intraperitoneally with article 1, article 2, or DMSO (vehicle) 30minutes before FA injection. The three folic acid treatment groups wereadministered a single intraperitoneal injection of FA (Sigma-Aldrich,St. Louis, Mo.) of 250 mg/kg in 0.3 mol/L sodium bicarbonate. Animalswere sacrificed 48 hours after treatment.

Plasma samples were collected at the time of euthanasia. Kidneys wereperfused in situ with cold saline before removal. One kidney was snapfrozen in liquid nitrogen for RNA and protein studies, and the other wasfixed and paraffin embedded to archive for histopathology analysis.

The effect of example compounds showed the efficacy in the FA-inducedAKI model by decreasing the creatinine and BUN to normal function andthe kidney with little damage compared with vehicle control. Frommolecular signal pathway, example compound can effectively decrease theexpression of RIPK3 and MLKL, which is associated with renalinflammation.

Finally, it should be noted that there are other ways to practice theinvention. Accordingly, embodiments of the present invention is to bedescribed as examples, but the present invention is not limited to thecontents described, further modifications may be made within the scopeof the present invention or the equivalents added in the claims.

All publications or patents cited herein are incorporated by referencein this invention.

Reference throughout this specification to “an embodiment”, “someembodiments”, “one embodiment”, “another example”, “an example”, “aspecific example” or “some examples” means that a particular feature,structure, material, or characteristic described in connection with theembodiment or example is included in at least one embodiment or exampleof the present disclosure. Thus, the appearances of the phrases such as“in some embodiments,” “in one embodiment”, “in an embodiment”, “inanother example, “in an example,” “in a specific example,” or “in someexamples,” in various places throughout this specification are notnecessarily referring to the same embodiment or example of the presentdisclosure. Furthermore, the particular features, structures, materials,or characteristics may be combined in any suitable manner in one or moreembodiments or examples.

Although explanatory embodiments have been shown and described, it wouldbe appreciated by those skilled in the art that the above embodimentscannot be construed to limit the present disclosure, and changes,alternatives, and modifications can be made in the embodiments withoutdeparting from spirit, principles and scope of the present disclosure.

What is claimed is:
 1. A compound of Formula (I)a or Formula (I)b, a pharmaceutically acceptable salts thereof, and individual enantiomers or diastereomers thereof:

wherein, z is 0 or 1; L is absent; or L is selected from C₁-C₁₀ alkyl, C₁-C₁₀ alkoxyl, C₃₋₇ cycloalkyl, C₁-C₁₀ alkylcycloalkyl, heterocycloalkyl, C₁-C₁₀ alkylheterocycloalkyl, C₅₋₁₀ aryl, C₁-C₁₀ alkylaryl, C₅₋₁₀ heteroaryl, and C₁-C₁₀ alkylheteroaryl; Q is selected from:

wherein, n is an integer selected from 0 to 10; each of R¹ and R² is independently selected from hydrogen and CH₃; each of R³ and R⁴ is independently selected from hydrogen and C₁-C₅ alkyl; each W is independently absent or is selected from O and S; and i) when W is absent, then R³ and R⁴, optionally, together form the following structure:

ii) when W is O, then OR³ and OR⁴ optionally, together form the following structure:

PEP is a peptidyl moiety having the following structure:

wherein, each asterisk (*) independently denotes a chiral center in either an (S) or (R) configuration; m is an integer selected from 0 to 10; X¹ is selected from hydrogen, —C(═O)—OR_(m), —S(O)—O—R_(m), —S(O₂)—O—R_(m), —S(O₂)—N—(R_(m))₂ and —C(═O)—N—(R_(m))₂, where R_(m) is C₁-C₆ alkyl, C₁-C₆ alkoxyl, C₁-C₆ alkenyl, C₁-C₆ haloalkyl, C₃-C₇ cycloalkyl, C₁-C₆ alkylcycloalkyl, C₃-C₇ heterocycloalkyl, C₁-C₆ alkylheterocycloalkyl, C₅-C₁₀ aryl, C₁-C₆ alkylaryl, C₅-C₁₀ heteroaryl, and C₁-C₆ alkylheteroaryl; each of X², X³ and X⁴ is independently selected from C₁-C₁₀ alkyl, C₁-C₁₀ alkenyl, C₅-C₆ aryl, C₁-C₆ alkylaryl, heteroaryl, and C₁-C₆ alkylheteroaryl; A is absent, or A is selected from Ala, Leu, Ile, Phe, Met, Pro, Gly, Ser, Thr, Cys, Tyr, Asn, Gln, His, Lys, Arg, Asp, Glu, and Val, each of which can be in either a D or L configuration; wherein the amino residue is either unprotected, or protected by a protecting group selected from Cbz and Fmoc; and G is absent, or G is selected from —O—, —S—, —NH—, —NH—C(═O)—O—, —O—C(═O)—NH—, —NH—C(═O)—NH—, —NHSO₂—, —SO—, —SO₂—, and —NHC(═O)—.
 2. The compound according to claim 1, wherein L is C₁-C₁₀ alkyl.
 3. The compound according to claim 1, wherein L is selected from C₅-C₁₀ aryl and C₁-C₁₀ alkylaryl.
 4. The compound according to claim 1, wherein L is selected from C₅-C₁₀ heteroaryl, C₁-C₁₀ alkylaryl, C₁-C₁₀ alkylheteroaryl, and pyridine.
 5. The compound according to claim 1, wherein G is absent or G is selected from —NHC(═O)—, —NHC(═O)—O—, and —NHSO₂—.
 6. The compound according to claim 1, wherein Q has the structure:

wherein, each W is independently absent; n is an integer from 1 to 3; R¹ is selected from hydrogen and methyl; and each R³ is independently C₁₋₃ alkyl.
 7. The compound according to claim 1, wherein PEP has the structure:

wherein, each asterisk (*) independently denotes a chiral center that can be either in an (S) or (R) configuration; X¹ is selected from —C(═O)—O—R_(m), —S(O)—O—R_(m), —S(O₂)—O—R_(m), —S(O₂)—N—(R_(m))₂, and —C(═O)—N—(R_(m))₂, where R_(m) is selected from C₁-C₆ alkyl, C₁-C₆ alkoxyl, C₁-C₆ alkenyl, C₁-C₆ haloalkyl, C₃-C₇ cycloalkyl, C₁-C₆ alkylcycloalkyl, C₃-C₇ heterocycloalkyl, C₁-C₆ alkylheterocycloalkyl, C₅-C₁₀ aryl, C₁-C₆ alkylaryl, C₅-C₁₀ heteroaryl, and C₁-C₆ alkylheteroaryl; each of X₂, X₃ and X₄ is independently selected from C₁-C₁₀ alkyl, C₁-C₁₀ alkenyl, C₅-C₆ aryl, C₁-C₆ alkylaryl, C₅-C₆ heteroaryl, and C₁-C₆ alkylheteroaryl; and A is absent or A is selected from Ala, Leu, Ile, Phe, Met, Pro, Gly, Ser, Thr, Cys, Tyr, Asn, Gln, His, Lys, Arg, Asp, Glu, and Val, each of which can be in either a D or L configuration; wherein the amino residue is either unprotected, or protected by a protecting group selected from Cbz and Fmoc.
 8. The compound according to claim 7, wherein A is absent or A is valine.
 9. The compound according to claim 7, wherein, X¹ is absent, or X¹ is selected from Et-O—C(═O)—, i-Pr-O—C(═O)—, t-Bu-O—C(═O)—, and cyclopropyl-CH₂—O—C(═O)—; X² is selected from i-propyl-CH₂—, cyclopropyl-CH₂—, cyclopentyl-CH₂—, and adamantyl-CH₂—; X³ is selected from Ph-CH₂— and Pyr-CH₂—; and X⁴ is selected from i-propyl-CH₂—, cyclopropyl-CH₂—, and cyclopentyl-CH₂—.
 10. The compound according to claim 7, wherein, A is absent; X¹ is selected from t-Bu-O—C(═O)—, cyclopropyl-CH₂—O—C(═O)—, and ethyl-CH₂—O—C(═O)—; X² is i-propyl-CH₂—; X³ is Ph-CH₂—; and X⁴ is i-propyl-CH₂—.
 11. The compound according to claim 7, wherein, A is absent; X¹ is t-Bu-O—C(═O)—; X² is selected from i-propyl-CH₂—, and adamantyl-CH₂—; X³ is Ph-CH₂—; and X⁴ is selected from cyclopropyl-CH₂—, cyclopentyl-CH₂—, and i-propyl-CH₂—.
 12. The compound according to claim 7, wherein, A is valine; X¹ is selected from t-Bu-O—C(═O)— and cyclopropyl-CH₂—O—C(═O)—; X² is selected from i-propyl-CH₂— and adamantly-CH₂—; X³ is Ph-CH₂—; and X⁴ is selected from i-propyl-CH₂—, cyclopropyl-CH₂—, and cyclopentyl-CH₂—.
 13. The compound of claim 1, wherein the compound is selected from:

or a pharmaceutically acceptable of any of the foregoing.
 14. A pharmaceutical composition comprising the compound according to claim 1 or a pharmaceutically acceptable salt thereof. 